Singular

Tests

770 questions about players, teams and the game, each answered with data. Each carries its answer (supported, not supported, mixed) and how far the evidence goes: tested only on the data it was found in, held out, or replicated on later data. Method.

770 tests

Asked and answered 14

Does sending players to the offensive glass leave a team open in transition?

No, in the NBA it costs almost nothing. For every 5 points of offensive rebound rate a team adds, opponents score +0.002 points per possession after its misses (90% interval −0.007 to +0.011); the cost would have to reach +0.086 to cancel the extra rebounds. Net, each 5 points of offensive rebound rate gains +6.6 points per 100 misses (5.6 to 7.5).

664,302 missed field goals in 180 team-seasons of play-by-play, 2020-21 to 2025-26. Each team's offensive rebound rate is compared with what opponents score on the possessions after its misses, within each season; the same team compared with itself from year to year gives the same answer. The net counts the possession the opponent gets afterwards. Intervals: 90%, resampling franchises. Blind to: how many players actually crash (offensive rebound rate is an outcome, not a count), and the controls for big men and team quality are partial.

Supportedq-crash

Should a coach sit a starter who picks up two early fouls?

Usually not. After a second foul in the first quarter a starter loses 3.9 game minutes against his normal (90% interval 3.8 to 4.0), and leaving him in keeps 8.5 more minutes while raising his foul-out risk from 3.5% to 10.2%. Priced in wins, leaving him in is worth +0.33 points of win probability per decision (+0.28 to +0.38), about 0.22 wins per team per season.

124,505 foul-trouble events at four trouble points (second foul in the first quarter through fifth foul in the fourth). Each starter is compared with himself in his other starts that season, at the same second of the game with fewer fouls. A simple model of when fouls arrive gives the minutes kept and the foul-out risk; the win value multiplies those minutes by the rating gap between the starter and the teammates who replace him. Intervals: 90%, resampling players; the decision-model intervals cover sampling only. Blind to: matchups, what the coach knows, and minutes coaches give back later (scaled to those, the win value is about half).

Supportedq-two-foul

How surprising is it that LeBron never had a single 27-point, 7-rebound, 7-assist game?

Only mildly. A model built from his own 1,622 games expects 1.65 games at exactly 27/7/7 (90% interval 1.29 to 2.05), so getting none happens about 19% of the time. Across all 1,191 players with 400+ games, 25.5% never posted their own rounded career line (23.4% to 27.5%).

Regular-season games with minutes above zero, players with 400+ games and nearly complete box scores, so this covers the modern box-score era. The model (a Gaussian copula) keeps each player's own spread of points, rebounds and assists and joins them with his own correlations between them; treating the three as independent predicts too few exact lines. Lines are rounded career averages. Intervals: 90%, resampling games.

Not supportedq-line

Did EPM, a leading public player rating, change its model?

Yes. Its 2025-26 values were re-issued between 7 Oct 2026 and 20 Oct 2026; for players with 500+ minutes the order barely moved (rank correlation 0.914, 90% interval 0.896 to 0.928), but the spread is 14% wider (10% to 17%). Singular's comparisons with EPM still stand, because they scored the values EPM published at the time.

Our saved copy of the table from 7 Oct 2026 against a fresh pull on 20 Oct 2026, matched player by player. Intervals: 90%, resampling players. The old season table rests on one archived copy, and past-season tables are now behind a subscription.

Supportedq-epm

Is an isolation-heavy offense easier to shut down in the playoffs?

No sign of it. For the same player in the same season, isolation and pick-and-roll plays lose 0.019 points per possession less from the regular season to the playoffs than his other plays (90% interval +0.006 to +0.032). Teams that lean on those plays do no worse in playoff series than their regular-season ratings predict (−0.89 points per 100 possessions per 10 points of share, −2.33 to +0.56); the test rules out a penalty larger than about 13 points of series win probability.

NBA.com Synergy play types, 2015-16 to 2025-26: 695 player-seasons compare each player's isolation and pick-and-roll-handler plays with his other plays, adjusted for the better defenses teams meet in the playoffs. The series test was declared before any outcome was computed: 919 games in 165 series, with a play-by-play stand-in for style that extends it back to 1996-97. Intervals: 90%, resampling players (play types) and team-seasons (series). Blind to: Synergy credits a pick-and-roll to the handler only when he finishes it, so a trap that forces a pass shows up elsewhere; only good teams reach the playoffs.

Not supportedq-iso

Does Stop%, the share of possessions a defender ends, measure good defense?

It measures something stable, but it adds nothing to existing defensive ratings. It carries over from season to season at r = 0.88, yet it tracks defensive RAPM (a lineup-based defense rating) less well than the box-score rating DBPM (0.33 against 0.50). Added to DBPM, it changes next-season prediction error by −0.01% (90% interval −0.06% to +0.05%).

Player-seasons from 2003-04 to 2025-26; the correlations use 6,013 player-seasons with 1,000+ minutes. The out-of-sample test fits on 2003-13 and predicts next season's defensive RAPM in 2014-24. Intervals: 90%, resampling players. Blind to: shot deterrence, positional defense and switching, which box scores do not see.

Not supportedClean nullq-stop-pct

Does preseason tell you anything about how a player's season will go?

Yes: a little for returning players, a lot for rookies. Tested on seasons the model never saw, preseason box scores add 0.023 to the share of variation explained (R²) in a second- or third-year player's season rating (90% interval 0.012 to 0.036), and 0.137 for rookies over draft slot and age (0.089 to 0.181). Among the top tenth of preseason-flagged risers, 71% beat their forecast, against 52% of all returning players.

Player-seasons with 60+ preseason minutes and 500+ regular-season minutes, preseasons 2005-06 to 2025-26. Each season is forecast by a model fit only on earlier seasons (walk-forward), with and without the preseason box score; the season rating is BPM (Box Plus/Minus). Intervals: 90%, resampling players. Blind to: stars resting in preseason, opponent quality and effort, and players whose bad preseason cost them their role (the minutes filter drops them).

Supportedq-preseason

Are high-level college shooters failing to make it in the NBA?

Not as a group. Shooters from the 2018-23 draft classes played 330 more NBA minutes in their first three seasons than other picks, both measured against what their draft slot predicts (90% interval −23 to +669). The gap did not shrink in recent classes (+198, −316 to +693), though the players the posts name are a real cluster of misses: 5 of 8 played less than their slot predicts.

Drafted players with a final college season in Jeremias Engelmann's public pre-draft data, classes 2010-25. A shooter made 38%+ of his threes on 5+ attempts per 40 minutes. Expected minutes come from a draft-slot curve; players who never played count as zero. Intervals: 90%, resampling players. Blind to: minutes measure opportunity, not quality; the 2024 and 2025 classes have one or two seasons.

Not supportedq-college-shooters

Do unstable rotations hold young players back?

We found no sign of it. Rotation habits belong to the coach (with the same coach, stability carries over at r = 0.54, 90% interval 0.46 to 0.62), but for players 23 or under, one standard deviation more stability goes with −0.155 BPM of development (−0.260 to −0.059), the opposite of the claim. Donovan's six Chicago teams sat about average (−0.020 against the season mean, −0.049 to +0.007).

390 team-seasons from lineup stints, 2013-14 to 2025-26. The measure compares each rotation player's minute-by-minute on-court pattern across every pair of games: 1 means the same minutes every night, 0 means they look random. Counting coach's-decision benchings changes almost nothing. Stable seasons do go with better results beyond the roster (+0.68 points per 100 per standard deviation, +0.42 to +0.96), but nothing shows the coach causes it. Intervals: 90%, cluster bootstrap. This is observational: injured rosters make rotations unstable, and good young players earn fixed roles.

Not supportedq-rotations

When a player's scoring role shrinks, do his rebounding and defense grow?

Mostly no, in either direction. When roster changes move a player's usage by 5 points, his defensive rebounds change by +0.08 per 36 minutes (90% interval −0.01 to +0.18) and his steals by 0.00 (−0.03 to +0.03). Fouls are the exception: they move against usage, −0.12 per 36 (−0.17 to −0.06), about equally whether usage rises or falls.

7,390 season-to-season pairs, 1998-99 to 2025-26. Usage moves for reasons outside the player's control: the scoring talent added to or lost from his roster. Rising and falling halves are tested separately. Intervals: 90%, resampling players, with a correction for testing six stats. A one-night version (teammates absent) agrees, and adds a small lineup-defense cost on those nights.

Not supportedq-reverse-usage

Has the league become friendlier to traditional centers?

Not over the last five seasons as a whole. At fixed box-score prices, lineups with a traditional center (6-10 or taller, few threes) gained +0.24 points per 100 possessions in 2021-26 against 2014-21 (90% interval −0.43 to +0.95), and their pay premium at equal production fell by 2.6 points of the salary cap (1.5 to 3.7). The 2025-26 season alone is the exception (interval +2.7 to +5.1); the 2026-27 season will test whether it lasts.

Lineup stints, 2008-09 to 2025-26. Each lineup's results are compared with what its players' box scores predict at fixed prices, and the traditional-center share is tested by season; the declared contrast is 2021-26 against 2014-21. Pay: salary as a share of the cap at equal past production. Intervals: 90%, resampling team-seasons. Blind to: listed heights changed measurement standard around 2019.

Not supportedq-centers

Does moving the ball fast (short touches, many passes) make for a better offense?

No. These habits are real team traits: touch length carries over from season to season at r = 0.63 (90% interval 0.55 to 0.69). But across 390 team-seasons, one standard deviation more passes per 100 possessions goes with −0.43 points of offensive rating (−0.75 to −0.23), with pace and last season's offense held fixed; pace itself shows nothing (+0.03, −0.26 to +0.33).

NBA.com team tracking (touches, passes, drives), 2013-14 to 2025-26, with possessions and offensive rating from box scores. Intervals: 90%, resampling franchises. The likely reason runs the other way: teams with a star creator hold the ball and score well. Six traits were tested, so one chance result is possible.

Not supportedq-pace

After a drive and kick-out, what should the player who catches it do?

Shoot, by a small margin, or make one patient pass. In 2015-16 tracking data, with the situation at the catch held fixed, the catch-and-shoot three beats any pass by +0.08 points per kick-out (90% interval 0.00 to +0.16, just touching zero), down from a raw gap of +0.20. A pass after one to two seconds scores about as well as the shot, or better (by +0.11, interval −0.01 to +0.24), and holding the ball longer is the worst choice (the shot beats it by +0.18, +0.03 to +0.34).

Raw SportVU tracking (player and ball positions 25 times a second) for 631 games of 2015-16. The detector was tuned on 150 games, frozen, then checked against the NBA's own drive counts (player-by-player r = 0.97). The adjusted values come from a model that sees all ten players and the ball at the catch, combined with a model of who chooses what. Intervals: 90%, resampling games. Blind to: help rotations and defender intent after the catch; points on one possession are mostly noise.

Mixedq-drive-kick

How many NBA minutes until a player's early numbers explain most of his career peak?

Many more than 1,143 on our data. Scored on players no rating weight had seen, Singular's forecast explains 36% of the variation in career peak at 1,143 minutes (90% interval 25% to 42%). It reaches half only at about 3,680 minutes (2,414 to 4,701).

1,416 players who debuted 1997-98 to 2016-17 and reached age 29. Every rating behind a test player's forecast was fitted only on seasons before his checkpoint, and the peak is scored on a scale fitted before the test players arrived. Intervals: 90%, resampling players; in 24% of resamples the forecast never reaches 0.5 by 5,000 minutes.

Mixedq-peak-minutes

Player ratings and SiPM 136

What did SiPM's fitted weights learn about offense and defense?

Defense leans on lineup data (lineups carry 81% of the defensive projection, 73 to 88) and offense on the box score (40%, 35 to 46): the direction DARKO's published blend takes.

SupportedIn sample onlyDefense leans on lineup data (lineups carry 81% of the defensive projection, 73 to 88)E08

Does a team built from players' prior-season SiPM ratings, at the minutes they actually played, have the net rating the ratings imply?

Adding up each player's SiPM from the season before, weighted by the minutes he went on to play, tracks the team's actual net rating closely: r = 0.81 over 540 held-out team-seasons, with a slope near 1 (0.98). The test is given the real minutes, so it checks the per-possession ratings, not a minutes forecast. Updated 2026-10-15: was r = 0.80 between minutes-weighted team SiPM and actual team net rating; slope 0.98 (r 0.79 to 0.82; slope 0.93 to 1.04 (90%, bootstrap of whole seasons)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 540 team-seasons, regular-season stints

SupportedHeld outr = 0.81 between minutes-weighted team SiPM and actual team net rating; slope 0.98 (r 0.80 to 0.83; slope 0.93 to 1.04 (90%, bootstrap of whole seasons))SP06

Does the sum of five players' SiPM forecast a lineup's net rating, and how much noise sits around it?

Across 14,274 held-out lineups with 50+ possessions each way, the sum of the five players' prior-season SiPM correlates with the lineup's net rating at r = 0.29. Average results rise steadily from about -6 to +10 per 100 across the ten forecast groups, while single lineups spread over about 36 points per 100 in every group.

Sample: 14,274 lineup-seasons, median 170 possessions

SupportedHeld outpossession-weighted r = 0.29 between summed SiPM and lineup net rating (0.28 to 0.30 (90%, bootstrap of whole seasons))SP07

Does that result hold on other dates?

Level, not ahead. On every game day of 2025-26 (135 dates) SiPM is level with DARKO (+0.148, 90% -0.197 to +0.386 after the 2026-10-07 rerun), and level in the weekly replays of 2025-26, 2024-25 and 2023-24; also level with EPM, xRAPM and the public average.

Sample: 135 dates

SupportedReplicated out of sample2025-26 daily replay, SiPM minus DARKO (primary rule): +0.141 (-0.174 to +0.382)E06

Frozen on January 6, 2026, did SiPM predict the rest of 2025-26's lineups as well as the public metrics?

Level with EPM: SiPM +0.077 (two-way 90% -0.067 to +0.220) after the 2026-10-07 rerun. Not ahead.

Sample: 689 games

SupportedHeld out+0.092 (two-way -0.049 to +0.234)E05a

Frozen on January 6, 2026, did SiPM predict the rest of 2025-26's lineups as well as the public metrics?

Ahead of DARKO at a 90% interval (+0.186, two-way +0.049 to +0.322) but level at the stricter 97.5% bar (-0.015 to +0.390), after the 2026-10-07 rerun.

Sample: 689 games

MixedHeld outAhead of DARKO at a 90% interval (+0.186, two-way +0.049 to +0.322)E05b

Does SiPM (Singular Plus-Minus: RAPM v3 + a box model + an age curve) beat a fair baseline, the plain RAPM-and-BPM average given the same machinery?

Yes, narrowly: SiPM (rerun 2 since 2026-10-09) removes +0.025 percentage points more next-season lineup error than the fair bar (90% +0.016 to +0.034), ahead in 16 of 18 held-out seasons.

Sample: 18 held-out seasons

SupportedHeld outSiPM minus fair bar (BBRef BPM, 250+ min): +0.028 percentage points of next-season lineup error (+0.018 to +0.036 (games); +0.019 to +0.036 (home teams))E04

Does our lineup-based rating (RAPM) reproduce the best public version?

Yes. Our pooled 10-season RAPM ranks players like Engelmann's public 10-year RAPM: rank correlation 0.95 (882 players).

Sample: 882 players

SupportedReplicated out of sampleOur pooled 10-season RAPM ranks players like Engelmann's public 10-year RAPME01

How much of a player's next three seasons can public data know?

About 38% of future RAPM, tested forward in time; about 65% is predictable at all. So public data reaches about half of the knowable (57%, 48%, 50% by era since 1998, with missing futures dropped; 61% if they are filled at −2, a basis choice still open).

SupportedHeld outAbout 38% of future RAPM, tested forward in timeE39

What does each public data layer add, era by era?

The full box score adds +11 to +15 points of future-RAPM R-squared and lineup data +5 to +6, in every era since 1998, intervals above zero.

SupportedHeld outThe full box score adds +11 to +15 points of future-RAPM R-squared and lineup data +5 to +6, in every era since 1998, intervals above zeroE40a

Does SiPM's lineup-level edge show up when ranking individual players?

A tie: SiPM minus the plain RAPM-BPM average is +0.0071 in rank correlation (-0.0035 to +0.0179), below the smallest gap the test could detect (0.0164). Two seasons ahead +0.0128 (+0.0012 to +0.0251). Status changed 2026-10-15: next season is still a tie, but two seasons ahead SiPM now beats the plain average (+0.0128, +0.0012 to +0.0251, an interval that excludes zero), so the evidence is split. Updated 2026-10-15: was Spearman gap vs plain average: +0.0060 (-0.0048 to +0.0161) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 6,320 player-seasons, 1,295 players

MixedHeld outSpearman gap vs plain average: +0.0071 (-0.0035 to +0.0179)SP03

What does each public data layer add, era by era?

Nine play-by-play measures add nothing; public tracking adds nothing measurable either.

Not supportedClean nullNine play-by-play measures add nothing; public tracking adds nothing measurable eitherE40b

At the top of SiPM's board, are non-creating bigs over-forecast relative to other players there?

When SiPM ranks a non-creating big in the season's top 30, his next-season impact comes in -0.36 points per 100 below the other top-30 players (-0.72 to -0.04) on current production (re-run 2026-10-10). It was -0.52 (-0.95 to -0.14) before the 2026-10-09 SiPM reruns (age term, one height standard, rim deterrence), which closed about a third of the gap. The rest of the cause is not found.

Sample: top 30: 540 rows, 82 NCB rows, 40 players

SupportedHeld out-0.36 points per 100 (top-30 NCB minus other top-30) (current production, re-run 2026-10-10; was -0.52) (-0.72 to -0.04 (90%; was -0.95 to -0.14))LR02

At the top of SiPM's board, are primary creators under-forecast?

Top-30 primary creators (usage and creation share in the top third) beat their SiPM forecast by +0.27 points per 100 against other top-30 players (+0.04 to +0.49); top 60 +0.17 (-0.00 to +0.34), which now touches zero. Updated 2026-10-15: was +0.28 (+0.03 to +0.52) and top 60 +0.19 (+0.01 to +0.37) before the 2026-10-09 SiPM reruns.

Sample: top 30: 540 rows, 316 creator rows

SupportedHeld out+0.27 points per 100 (top-30 creators minus other top-30) (current production, re-run 2026-10-10; was +0.28) (+0.04 to +0.49 (90%; was +0.03 to +0.52))LR03

Are SiPM's walk-forward forecasts of non-creating bigs biased on next season's on-court impact?

Not supported overall. Across all non-creating-big seasons (6-9+, creation share below median) the next-season residual is -0.12 points per 100 against other players (-0.24 to +0.01).

Sample: 4,209 player-seasons, 920 players; player bootstrap 2,000

Not supportedClean null-0.06 points per 100 (NCB minus others) (current production, re-run 2026-10-10; was -0.12) (-0.18 to +0.06 (90%; was -0.24 to +0.01))LR01

Is the NCB residual worse after a trade, a summer opening, a starter promotion or a usage/minutes jump?

Not supported. Team change +0.04 (-0.20 to +0.28), summer usage opening +0.01 (-0.23 to +0.25), starter promotion +0.18, usage +3 -0.18, minutes +6 -0.16: no difference in differences excludes zero. Updated 2026-10-15: numbers from the 2026-10-10 re-run (team change was +0.06).

Sample: 4,209 player-seasons, 920 players; player bootstrap 2,000

Not supportedClean null+0.04 change in the NCB gap at a team change (current production, re-run 2026-10-10; was +0.06) (-0.20 to +0.28 (90%; was -0.19 to +0.29))LR04

Do low minutes per game, or the role part of SiPM's forecast, account for the LR02 gap?

Not under the declared rule. top 60: explains -9% of the gap; slope for these bigs −0.04 (90% −0.25 to +0.16); top 30 explains 34%. Role part: top 60: explains -8% of the gap; slope for these bigs −0.07 (90% −0.23 to +0.07); top 30 explains 14%.

Sample: 1080 top-60 rows, 229 non-creating-big rows

Not supportedHeld outTop-60 gap explained -9% (slope for non-creating bigs −0.25 to +0.16 (90% player bootstrap))LR10

Does rebound rate account for the LR02 gap?

Not under the declared rule. top 60: explains 52% of the gap; slope for these bigs −0.17 (90% −0.42 to +0.06); top 30 explains 1%. Across all rows, heavy rebounders outside the group are under-forecast (slope +0.09, +0.02 to +0.14): a lead that rebounds are worth different amounts by type.

Sample: 1080 top-60 rows, 229 non-creating-big rows

Not supportedHeld outTop-60 gap explained 52% (slope for non-creating bigs −0.42 to +0.06 (90% player bootstrap))LR11

Does the luck/gravity increment of the lineup rating account for the LR02 gap?

Not under the declared rule. top 60: explains 1% of the gap; slope for these bigs −0.01 (90% −0.20 to +0.16); top 30 explains 3%.

Sample: 1080 top-60 rows, 229 non-creating-big rows

Not supportedHeld outTop-60 gap explained 1% (slope for non-creating bigs −0.20 to +0.16 (90% player bootstrap))LR12

Is SiPM systematically wrong about high-usage players?

Not detectably. Held out over 18 seasons, high-usage players' lineups beat SiPM's forecast by +0.06 per 100 more than everyone else's (−0.07 to +0.20); with the forecast level held fixed, −0.01 (−0.14 to +0.13). SiPM's box-plus-lineup blend removes the lineup-only bias of SD02. Updated 2026-10-15: was +0.10 per 100 (high-usage minus rest) (90% player bootstrap −0.04 to +0.24) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 4,311 player-seasons, 947 players; high-usage = top 10% usage in t (469 rows)

Not supportedClean null+0.06 per 100 (high-usage minus rest) (90% player bootstrap −0.07 to +0.20)SD03

Do lineup-based impact forecasts under-rate high-usage players' next-season on-court impact?

Held out, a forecast built only from our lineup rating (the analogue of EPM or xRAPM) left high-usage players' next-season lineups +0.29 per 100 better than forecast relative to everyone else (+0.15 to +0.43), mostly on offense (+0.25). A box-only forecast also under-forecast them (+0.21). Updated 2026-10-15: was +0.30 per 100 (high-usage minus rest, lineup-only forecast) (90% player bootstrap +0.17 to +0.44) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 4,311 player-seasons, 947 players; high-usage = top 10% usage in t (469 rows)

SupportedHeld out+0.29 per 100 (high-usage minus rest, lineup-only forecast) (90% player bootstrap +0.15 to +0.43)SD02

For high-usage players whose box and lineup ratings disagree (box higher), which one predicts next season better?

The reverse. For high-usage players whose box rating most exceeds their lineup rating, next-season lineups fell short of SiPM by −0.24 per 100 relative to other high-usage players (−0.52 to +0.03), not distinguishable from zero, and short of a box-only forecast by −0.74 (−1.03 to −0.45). The lineups were closer. Updated 2026-10-15: was SiPM residual −0.32 per 100; box-only −0.97 (90% player bootstrap −0.58 to −0.03; −1.26 to −0.64) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 162 box-over-lineup high-usage rows vs 307 other high-usage rows

Not supportedHeld outSiPM residual −0.24 per 100; box-only −0.74 (90% player bootstrap −0.52 to +0.03; −1.03 to −0.45)SD04

Does one postseason say much about a player beyond his regular season?

Not much: one postseason's lift over his regular season is about 4% player and the rest noise, and B15's lineup test gained 0.037% of the error. But a small riser trait is detectable over careers (RI01); the earlier line 'no separate playoff skill is large enough to detect' was withdrawn.

Not supportedClean nullletting playoff lineups move his rating improves held-out playoff predictions by a median 0.04% of the errorB15

Do some players reliably rise or fall in the playoffs?

Not across years: it holds within one playoff run (split-half 0.33) but does not repeat the next year (r 0.04, -0.01 to 0.09). Usage translation repeats weakly (r 0.17).

Sample: 1,606 rows

Not supportedIn sample onlyNext-year r for box translation 0.04; usage translation 0.17 (-0.01 to 0.09)TB16

Is Durant's drop an isolated case?

Eight public top-100 players drop 30+ places on January 6 (Aaron Gordon, Durant, Amen Thompson, Tari Eason, Aaron Nesmith, Ja Morant, Josh Giddey, Julius Randle), and 23 do in the 2026-27 projection.

Sample: 485-player common set

SupportedIn sample only8 players drop 30+ places on Jan 6; 23 in the projectionDD04

Within each height bucket, what separates the best players?

Scoring leads in every bucket. Only vision's share differs: smaller for guards than wings (−0.13, 90% −0.22 to −0.01; permutation p 0.008).

SupportedHeld outsmaller for guards than wings (−0.13, −0.22 to −0.01; permutation p 0.008)E18

Why does SiPM rank Durant about 105th when public models have him about 14th?

In 2024-25 Phoenix teammates shot +2.0 points per 100 above their usual rates with Durant on; SiPM treats that as luck and its chain carried 75% into this season. His Jan 6 lineup rating is 1.03 vs 4.21 on a plain three-season average, the biggest gap of 485 players. Without the luck adjustment he ranks 38th; without the over-35 age term as well, 12th.

SupportedIn sample onlyLineup rating 1.03 vs 4.21 (plain three-season); rank 106 -> 38 (no luck adj.) -> 12 (no luck, no age term)DD02

Has SiPM forecast a Durant decline each preseason that his lineup results did not show?

Partly, and not lately. His lineups beat the SiPM forecast in Brooklyn (2021-22 +3.04, 2022-23 +1.18 per 100). From 2023-24 they landed on it (−0.34, +0.11, −0.03) while the forecast fell from 5.0 to 2.2. Pooled 2023-24 to 2025-26: −0.50 (−2.25 to +1.69).

Sample: Residual RAPM for every player 2008-09 to 2025-26; Durant 200 game resamples per season

MixedHeld outResidual vs SiPM forecast, pooled 2023-24 to 2025-26: −0.50 per 100; pooled 2020-21 to 2025-26: +1.35 (90% game-resample intervals −2.25 to +1.69; −0.19 to +3.06)DD05

Do one-season drops in defensive lineup rating by players aged 21-25 persist?

About half persists. Players aged 21-25 whose one-season defensive RAPM fell 2+ points below their two prior seasons got back 0.56 of the drop next season (+0.49 to +0.63, 167 drops); 'half or more' is not determined. Older players and rises behave the same way: plain regression to the mean.

Sample: 455 drops of 2+ points, 167 at ages 21-25; 5563 rows in the all-rows regression

MixedIn sample onlyShare of the drop back next season 0.56 (90% player bootstrap 0.49 to 0.63)SD07

After a young player's one-season defensive drop, does SiPM's walk-forward defensive forecast miss in a consistent direction?

No. In the season after a 2+ point drop, young players' lineups defended −0.04 per 100 relative to SiPM's forecast compared with other young players (−0.25 to +0.18). SiPM already expects about half to come back. Updated 2026-10-15: was Defensive miss after drops minus other young rows −0.05 per 100 (90% player bootstrap −0.26 to +0.17) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 100 drops, 1289 rows

Not supportedHeld outDefensive miss after drops minus other young rows −0.04 per 100 (90% player bootstrap −0.25 to +0.18)SD08

Does scaling SiPM's defensive part by k < 1 lower its error on next season's lineups?

No. Production (k = 1) is best. Keeping 90% of the defensive part changes the held-out score by −0.0019 (−0.0038 to −0.0001); keeping 75% by −0.0114 (−0.0160 to −0.0072). A k picked walk-forward also loses (−0.0022).

Sample: 18 target seasons; dpm_v3 T2 harness reproduced exactly (0.6419) before any variant was read

Not supportedHeld outBest k = 1.00; k = 0.90 −0.0019, k = 0.75 −0.0114 points of % error removed (90% season-cluster bootstrap: k = 0.90 −0.0038 to −0.0001; k = 0.75 −0.0160 to −0.0072)DS01

Does SiPM's luck adjustment earn its place?

Dropping the luck adjustment costs clear held-out accuracy (-0.0106, -0.0141 to -0.0069; ahead in only 3 of 18 seasons), even though it would put Durant at 40th. Durant's 2024-25 bonus did not repeat. Updated 2026-10-15: was No-luck-adjustment minus current held-out score: -0.0112 (-0.0147 to -0.0074) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 18 held-out seasons

SupportedHeld outNo-luck-adjustment minus current held-out score: -0.0106 (-0.0141 to -0.0069)DD03

Should SiPM's luck adjustment spare the part of teammate shooting that a player causes?

Adopted into production SiPM on 2026-10-06, on top of C12. Sparing the part of teammates' shooting a player causes scores level with C12 alone held out (-0.0001, -0.0005 to +0.0002) and level on the lineup rating's own next-season test (+0.0003, -0.0006 to +0.0011). It barely moves Durant (106th to 104th of 485 on January 6; 81st to 83rd in the 2026-27 projection). Updated 2026-10-15: was Held-out score minus current: -0.0001 (-0.0004 to +0.0003) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 18 held-out seasons; 500 paired game resamples

SupportedHeld outHeld-out score minus current: -0.0001 (-0.0005 to +0.0002)GR05

Does fading a luck correction faster improve SiPM?

Carrying one season's luck at about 0.33 instead of 0.75 moves flagged players most toward the public ranks (Durant 106 to 90) but passes the held-out rule by a hair (-0.0011, -0.0022 to +0.00003). It is an engineering choice, not a gravity finding.

Sample: 18 held-out seasons

MixedHeld outHeld-out score minus current: -0.0011 (-0.0022 to +0.00003)GR06

Does crediting defenders' effect on opponents' three-point residuals in the luck adjustment change held-out accuracy?

Letting each defender's estimated effect enter the expected rate of the threes he defends raises SiPM's held-out score: production G plus defenders minus G +0.0017 (+0.0008 to +0.0027); full joint J +0.0016 (+0.0007 to +0.0026). The offensive joint estimate alone is level (+0.0003). Ratings move little (2025-26 rank correlation 0.9994).

Sample: 18 held-out seasons; 500 paired game resamples

SupportedHeld outHeld-out score, G + defenders minus G: +0.0017 (+0.0008 to +0.0027)GR12

Do defenders' estimated effects on opponents' three-point residuals predict next season's residuals?

Adding the five defenders to the joint gravity model improves next-season prediction of three-point residuals (+0.0040, +0.0019 to +0.0062), but the defensive part does not follow players who change teams.

Sample: Walk-forward three-season windows

SupportedHeld outHeld-out JOD minus JO +0.0040 % of squared error (+0.0019 to +0.0062)GR10

Do opponents' three-point residuals while a player is on defense persist for players who change teams, beyond shuffle and noise nulls?

Untested. The luck adjustment also scores opponents' threes and free throws at their expected rates, so a defender who contests well loses that credit. G spares measured gravity on offense only.

Not supportedClean nullTeam-changer next-season r of defensive coefficients 0.011 (-0.023 to 0.046)GR09

Is the opponents' shooting luck that SiPM removes from a player's defense persistent?

Mostly not. Opponents' three-point and free-throw luck with a player on court repeats year to year with r = 0.11 (0.08 to 0.15). Edwards's 2021-22 to 2024-25 mean of −1.36 per 100 is therefore worth about a tenth of that as skill. Added after seeing results.

Sample: 2,279 player pairs

Not supportedIn sample onlylag-1 r = 0.11 (90% player bootstrap 0.08 to 0.15)SD06

Should a coach's minutes decisions inform a low-minute player's rating?

A prior from minutes, starts and bench depth scores +0.0016 against the old SiPM held out (-0.0026 to +0.0053), level, and pulls flagged low-minute bigs toward the public view (Paul Reed 45th to 104th on Jan 6). Adopted on 2026-10-05.

Sample: 18 held-out seasons

SupportedHeld outChange 1 minus old SiPM: +0.0016 (-0.0026 to +0.0053)SP01

Should the age curve depend on how good a player is?

Alone it is level on accuracy (-0.0002, -0.0008 to +0.0004) and lifts Curry, Durant, Harden and LeBron, but failed one face-validity guard. Adopted together with the minutes prior (C12).

Sample: 18 held-out seasons

MixedHeld outChange 2 minus old SiPM: -0.0002 (-0.0008 to +0.0004)SP02

Should SiPM's single age curve depend on how explosive a player's game is?

None of three candidates passes the declared rule on the current SiPM (C12 plus G). The reliance term is level on next-season lineups (-0.00005 percentage points of error, 90% -0.00172 to +0.00168) but worse in the player-level test; decline signals are now level (+0.00022, -0.00014 to +0.00054). SiPM unchanged. Updated 2026-10-15: was Reliance term vs current SiPM, lineup test: +0.00029 percentage points of error removed (-0.00028 to +0.00101) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 18 seasons

Not supportedHeld outReliance term vs current SiPM, lineup test: -0.00005 percentage points of error removed (-0.00172 to +0.00168)TA09

Does carrying each player's lineup correction into the next season, and scoring shots at the shooter's own rate (RAPM v3), improve the rating?

Yes against 3-season xRAPM: +0.041 percentage points of next-season error removed (90%: +0.033 to +0.050), ahead in 16 of 18 held-out seasons. Since 2026-10-06 the luck adjustment spares measured gravity (variant G), +0.0003 over the luck-only version. Updated 2026-10-15: was +0.036 percentage points of next-season error removed (+0.028 to +0.045) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

SupportedHeld out+0.041 percentage points of next-season error removed (+0.033 to +0.050)E03

Which public-data rating best predicts next season's lineups?

Three-season RAPM with a box-score prior (xRAPM) removes the most error: 0.590% of a no-player baseline, against 0.520% for 3-season RAPM and 0.503% for BPM (28 seasons, each predicted forward).

Sample: 28 seasons

SupportedHeld out0.590% of a no-player baseline, against 0.520% for 3-season RAPM and 0.503% for BPM (28 seasons, each predicted forward)E02

Do some players beat (or miss) their forecasts year after year?

Partly. Baseline efficiency misses do not repeat from season to season. SiPM's lineup misses repeat slightly, mostly among stars (Curry and Kawhi most under-forecast). A correction built on each player's past misses does not improve held-out forecasts. Durant: no decline-that-never-came lately (DD05). Updated 2026-10-15: was SiPM lag-1 r of player misses 0.052; stars 0.19 (0.020 to 0.083; 0.08 to 0.29 (stars)) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 6,525 baseline rows / 1,288 players

MixedHeld outSiPM lag-1 r of player misses 0.050; stars 0.17 (0.018 to 0.080; 0.06 to 0.27 (stars))FM02

Do SiPM's lineup forecast errors repeat for the same player?

Slightly: lag-1 r 0.050 (0.018 to 0.080), above the permutation null; stars 0.17 (0.06 to 0.27) with a mean miss of +0.33 per 100 (0.10 to 0.52). Curry and Kawhi are the most persistently under-forecast, but no single player's mean is beyond 2 standard errors. Updated 2026-10-15: was Lag-1 r 0.052; player share 3.8% (null 95th pct 1.9%); stars lag-1 r 0.19 (0.020 to 0.083; 0.08 to 0.29 (stars)) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: Residual RAPM; permutation null

SupportedHeld outLag-1 r 0.050; player share 3.5% (null 95th pct 1.8%); stars lag-1 r 0.17 (0.018 to 0.080; 0.06 to 0.27 (stars))FM06

Does the gap between SiPM's box part and lineup part predict its next miss?

Players whose box part exceeds their lineup part keep falling short of SiPM; the reverse keep beating it. Each SD of the gap moves the next miss by -0.10 points per 100 (-0.14 to -0.06). Held out (added after the declared results), the gap alone cuts error by 0.41%.

Sample: 4,311 player-seasons, 947 players

SupportedHeld out-0.10 points per 100 per SD of gap (in sample); held-out MSE gain 0.0100 (-0.14 to -0.06; held out 0.0013 to 0.0195)PM03

If injury seasons are removed, do the same players stay persistently under- or over-forecast?

Mostly not. The named under-forecast players (Curry, Leonard, Hill, Embiid) beat the forecast in injury seasons too, and removing the injury effect makes their misses larger. On clean seasons alone the stable player share is 2.8% (shuffle null 95th percentile 3.3%, p 0.082); player means correlate 0.821 with the all-season means.

Sample: 4,311 player-seasons, 947 players

Not supportedIn sample onlyPlayer means, all vs clean seasons: r 0.82; top 20 kept: 10 under, 9 over (Clean-only stable share 2.7% vs null 95th pct 3.3%)PM02

Do traits, draft, gravity, injury history and the box-lineup gap together explain the persistent part?

Mixed. All tested inputs together cut the stable player share (from 3.2% to 2.1%), but do not improve held-out error: MSE gain -0.0178 (-0.0384 to 0.0004), now not distinguishable from zero.

Sample: 3,618 scored player-seasons

MixedHeld outStable share 3.2% to 2.1%; MSE gain -0.0178 (-0.0384 to 0.0004)PM10

Does the box score over- or under-translate into lineup impact for particular box profiles?

The declared block (gap plus gap x five traits) does not help held out: gain -0.0018 (-0.0153 to 0.0096).

Sample: 3,618 scored player-seasons

Not supportedClean nullMSE gain -0.0022 (-0.0157 to 0.0094)PM04

Are players whose box value comes from assists, steals and rebounds rather than points over-forecast?

Not supported. A non-scoring box index (mean z of assists, steals and defensive rebounds, minus z of points) has slope +0.034 on the next miss (-0.009 to +0.080), the wrong sign if anything. Rondo fits the profile; Marion and Calderon only moderately.

Sample: 4,311 player-seasons, 947 players

Not supportedClean nullSlope +0.032 per index unit (-0.010 to +0.078)PM05

Do players whose teammates shoot above their norms keep beating SiPM?

Not supported. The teammate three-point residual while he is on offense (3-season mean) has an in-sample slope of -0.052 (-0.089 to -0.013), the wrong sign, and does not help held out (gain -0.0011).

Sample: 3,618 scored player-seasons

Not supportedClean nullHeld-out MSE gain -0.0002 (-0.0046 to 0.0042)PM07

Does a player-level correction improve forecasts?

It does not. SiPM, all players: 0.41% of error removed (-0.06 to 0.89%). The star-only variant (added after results) now finds no stable star component in earlier seasons and makes no correction (0.00%).

Sample: 3,618 SiPM rows

Not supportedClean nullError reduced: SiPM all players 0.41%; stars 0.00% (-0.08 to 0.86%; no correction made (stars))FM07

Do an opponent adjustment or strictly walk-forward priors change SiPM?

No. Opponent adjustment −0.001 (−0.002 to +0.001); strictly walk-forward priors 0.000 (−0.001 to +0.001).

Not supportedClean nullOpponent adjustment −0.001 (−0.002 to +0.001)E07

Can a minutes model beat "same minutes as last season"?

Yes: error 5.5 vs 6.1 minutes a game; against a fitted line on last season's minutes −0.25 (−0.29 to −0.21, earlier run). The 2026-27 projection's top three: Gilgeous-Alexander, Jokić, Wembanyama.

SupportedHeld outagainst a fitted line on last season's minutes −0.25 (−0.29 to −0.21, earlier run)E11

Does the year-to-year reliability of SiPM's lineup part differ for non-creating bigs?

Not the cause. Non-creating bigs' one-season RAPM does repeat less (0.31 vs 0.42; difference −0.19 to −0.04), but their forecast misses do not grow with the lineup part of the forecast (top 60: explains -3% of the gap; slope for these bigs −0.03 (90% −0.35 to +0.20); top 30 explains 21%).

Sample: 1080 top-60 rows, 229 non-creating-big rows

Not supportedHeld outTop-60 gap explained -3% (slope for these bigs −0.35 to +0.20 (90% player bootstrap))LR09

Does a player's playoff-minus-regular-season box production repeat across his postseasons?

Yes, but small. The playoff lift in Game Score per 75 has a between-player spread of 0.55 (0.38 to 0.67); the regular-season spread is 3.83. One postseason is about 4% signal.

Sample: 3782 player-postseasons, 1061 players; 1924 consecutive pairs

SupportedIn sample onlytrait SD 0.55 Game Score per 75; next-postseason r +0.046 (SD 0.38 to 0.67; r +0.008 to +0.083 (90%, player-cluster bootstrap))RI01

Does the lineup-based playoff lift repeat?

Mixed: net lift repeats weakly (r +0.079, +0.034 to +0.121), but neither offense (+0.026) nor defense (-0.013) repeats alone.

Sample: 2696 player-postseasons

MixedIn sample onlytrait SD 1.44 points per 100; r +0.079 (SD 0.84 to 1.84; r +0.034 to +0.121)RI07

Does the sum of prior-season SiPM defensive ratings under-predict points allowed by lineups with primary creators?

Yes, about 0.3-0.5 per 100 per handler: 1 handler +0.51 (+0.21 to +0.82), 2+ +0.80 (+0.44 to +1.16) beyond the rating sum, against lineups with none. Held out, adding handler counts does not improve prediction. Updated 2026-10-15: was 1 handler +0.48, 2+ handlers +0.75 points allowed per 100 beyond the rating sum (vs 0 handlers) (90% team-season bootstrap +0.18 to +0.78; +0.38 to +1.11) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 1,190,442 defensive stints, 4,201,860 possessions, 540 team-seasons

SupportedIn sample only1 handler +0.51, 2+ handlers +0.80 points allowed per 100 beyond the rating sum (vs 0 handlers) (90% team-season bootstrap +0.21 to +0.82; +0.44 to +1.16)HS02

Fitted on our game logs, do per-stat half-lives follow the order Kostya (How DARKO Forgets) reports?

Yes. Next-game half-lives: starting 2.3 days, minutes 7.9, usage 62, 3PA per 36 68, FT% 301, rim % 445, 3P% 1225. Rank correlation with Kostya's eight: 0.95.

Sample: 736,297 player-games 1996-97 to 2025-26; as-of games 2001-02 on

SupportedIn sample onlySpearman 0.95 between our next-game half-lives and Kostya's (8 stats) (0.91 to 0.95 (90%, 300 player bootstraps))SM01

Does the best half-life change when the target moves from the next game to the rest of the season to next season?

Yes. Starting: 2.3 days for the next game, 66 for the rest of the season, 189 for next season. Shooting percentages barely change with the horizon.

Sample: 736,297 player-games

SupportedIn sample onlyStarting half-life 2.3 -> 66 -> 189 days; minutes 7.9 -> 68 -> 130 (next game 2.2 to 2.4; rest of season 62 to 68 (starting, 90% player bootstrap))SM02

Out of sample, does giving each stat its own half-life beat one shared half-life?

Yes, walk-forward 2006-07 to 2025-26: +2.5% lower squared error on the next game, +3.0% on the rest of the season (22 stats). The project's in-season layer is already per-stat; refitting it adds +0.29%.

Sample: 22 stats

SupportedHeld outMSE cut vs shared: next game +2.51%, rest of season +3.04% (+2.46 to +2.56%; +2.89 to +3.21% (90% player bootstrap))SM03

For next-season box-score inputs, do per-stat half-lives refit on the next-season target beat the current inputs and fixed season windows?

Yes: +2.1% lower error over 14 box stats (held out 2013-14 to 2024-25), +5.9% vs the 1/0.75/0.5 season window, +1.6% vs production FT% and 3P%.

Sample: fit on season ends 2001-02 to 2012-13, test 2013-14 to 2024-25 (5,060 rows for points)

SupportedHeld outMSE cut vs current decay +2.06% (14 stats); vs shared +1.38%; vs last season +7.28% (+1.54 to +2.56%; +1.16 to +1.62%; +6.66 to +7.85% (90% player bootstrap))SM04

Does rebuilding SiPM's box component with the next-season per-stat half-lives improve dpm_v3's T2 test?

Yes: +0.0035 points of lineup error removed (12 of 18 seasons); +0.0042 with FT% and 3P% too. Adopted into production SiPM on 2026-10-07 (variant NP, with the injury clock; SP08).

Sample: Held-out targets 2008-09 to 2025-26 (18 seasons)

SupportedHeld outT2 change +0.0035 (N), +0.0042 (NP); targets 2014-15 on +0.0030 (N) (+0.0022 to +0.0047; +0.0028 to +0.0056; +0.0015 to +0.0046 (90%, 500 game resamples within seasons; team resampling similar))SM05

Is the SiPM gain from the horizon or from per-stat memory?

Not distinguishable from zero: +0.0012 (-0.0001 to +0.0026); -0.0001 on targets from 2014-15. Per-stat beats shared by +0.0023.

Sample: Held-out targets 2008-09 to 2025-26

Not supportedClean nullT2 change +0.0012; N minus S +0.0023 (-0.0001 to +0.0026; +0.0011 to +0.0035 (90%, game resamples))SM06

On the first games after long absences, does darko_lite's Kalman filter beat its decay layer by more than usual?

Yes: after 250+ days out, the Kalman filter's next-10-game error is 11% below the decay layer's, against 0.4% on other games. The decay layer pulls a returning player toward the league average.

Sample: 917 games, 14 box stats

SupportedHeld outMSE ratio filter / decay 0.887 after 250+ days out vs 0.996 elsewhere (0.866 to 0.907; difference -0.129 to -0.089 (90% player bootstrap))SM07

Does a decay layer with a player-level prior after long absences improve post-return forecasts and SiPM?

Mixed. Replacing the league prior with the player's own level after a return helps after 41+ games out (-5.6% reducible error) but hurts after shorter absences (+0.6%) and nudges the SiPM box rating the wrong way. Not adopted; the clock rule (LY09) does better.

Sample: Test window 1,399 returns by 462 players (104 after 41+ games out, 26 after 82+)

MixedHeld outReducible error vs current, games 1-25: 41+ -5.6%; 82+ -8.0%; under 41 +0.6%; box rating all +0.13% (-7.9 to -2.8%; -12.8 to -2.1%; +0.1 to +1.1%; +0.04 to +0.23% (90% player bootstrap))SM10

Does a team's preseason net rating improve the project's preseason SiPM forecast of its regular-season net rating, out of sample?

Walk-forward over 480 team-seasons (2010-11..2025-26), adding shrunk preseason net to the feasible SiPM roster forecast cuts squared error by 0.98 (R-squared 0.485 to 0.527); better in 12 of 16 seasons.

Sample: 480 team-seasons; NBA.com preseason logs. Era check: LC-AGE-2005 (2006): Per 100 possessions and centred per season; not otherwise relevant; LC-LOCKOUT-2011 (2011): 2 preseason games: kept, shrinkage gives them little weight; ST-T03 (2012): Per 100 possessions and centred per season; not otherwise relevant; LC-B2B-2015 (2015): Regular-season schedule only: not relevant to preseason games; LC-CAP-2016 (2016): Per 100 possessions and centred per season; not otherwise relevant; ST-T15 (2016): Per 100 possessions and centred per season; not otherwise relevant; LC-TO-2017 (2017): Per 100 possessions and centred per season; not otherwise relevant; LC-REST-2017 (2017): Starters sit more: F3 weights games by regulars' minutes share; LC-SCHED-2017 (2017): Preseason shortened (earlier start): reliability shrinkage + F3 x post-2017 interaction; LC-CBA-2017 (2017): Per 100 possessions and centred per season; not otherwise relevant; ST-T10 (2017): Load management: same as LC-REST-2017; LC-1819-RULES (2018): Per 100 possessions and centred per season; not otherwise relevant; LC-BUBBLE-2019 (2019): Preseason of 2019-20 played normally (Oct. 2019): kept; LC-RESTLABEL-2019 (2019): Data labels only: not used; LC-72G-2020 (2020): Short preseason (Dec. start): kept, shrinkage; LC-TAKE-2022 (2022): Per 100 possessions and centred per season; not otherwise relevant; ST-T11F (2022): Per 100 possessions and centred per season; not otherwise relevant; LC-CUP-2023 (2023): Per 100 possessions and centred per season; not otherwise relevant; LC-PPP-2023 (2023): Regular-season participation rule: may raise star minutes in RS, not preseason; not modelled; LC-CBA-2023 (2023): Per 100 possessions and centred per season; not otherwise relevant

SupportedHeld out-0.92 MSE change (current production, re-run 2026-10-10; was -0.98) (-1.38 to -0.45 (90%; was -1.46 to -0.49))PS01

Do Kostya's preseason correlations replicate on our seasons?

On NBA.com logs 2005-06..2025-26, preseason net correlates 0.34 with regular-season net (Kostya: 0.32); R-squared rises 0.354 to 0.407 when added to last season's net (Kostya: 0.27 to 0.35).

Sample: 630 team-seasons

SupportedIn sample onlyr = 0.338; R-squared gain +0.053 (r 0.28 to 0.40; gain 0.031 to 0.081 (90%))PS02

Because starters sit in preseason, do games with more regulars' minutes carry more signal?

Head to head, regulars-weighted preseason net (F3) against raw net (F1): MSE change -0.04, not distinguishable from zero; regulars' plus-minus (F4) scored no better.

Sample: 480 team-seasons; regulars = top 8 by forecast minutes; regulars played 55% of preseason minutes

Not supportedClean null-0.023 MSE change (current production, re-run 2026-10-10; was -0.039) (-0.101 to +0.057 (90%; was -0.119 to +0.038))PS03

How much of the SiPM team forecast's error comes from not knowing minutes?

Giving SiPM the real minutes instead of last season's cuts squared error by 4.16, about 4 times what preseason net adds. Feasible SiPM r = 0.69; real minutes r = 0.81.

Sample: 480 team-seasons

SupportedHeld out-4.25 MSE change (current production, re-run 2026-10-10; was -4.16) (-5.21 to -3.30 (90%; was -5.17 to -3.16))PS05

Does Kostya's recursion (box prior -> RAPM -> refit box to that RAPM -> repeat) beat the project's one-step box prior on held-out next-season lineups?

No. After 10 rounds the production lineup rating predicts next season's lineups worse than round 1 (the current one-step prior): difference -0.086 (90% -0.111 to -0.062 over seasons); one-season rating -0.096.

Sample: 18 held-out target seasons

Not supportedHeld outProduction chain round 10 minus round 1: -0.086 (score = % of lineup error removed) (-0.111 to -0.062 (seasons); -0.098 to -0.075 (games))KR01

Is ridge toward zero the wrong prior for RAPM?

Yes, by a wide margin: the one-season rating with a walk-forward box prior removes +0.148 more next-season lineup error than plain RAPM (+0.133 to +0.163); the production chain +0.197. Ahead in 18 of 18 seasons. Kostya's first point; the project has used it since xRAPM.

Sample: 18 held-out target seasons

SupportedHeld outOne-step box prior minus ridge toward zero: +0.148 (+0.133 to +0.163 (seasons); +0.139 to +0.156 (games))KR02

Does swapping V3 for the recursive version improve SiPM on its declared test?

No. SiPM refit with the round-10 lineup part scores 0.023 below SiPM held out (-0.030 to -0.017); with round 2 (added afterwards) -0.007 (-0.011 to -0.003).

Sample: 18 held-out target seasons

Not supportedHeld outSiPM with round-10 lineup part minus SiPM: -0.023 (-0.030 to -0.017 (seasons); -0.028 to -0.019 (games))KR04

Is there a useful early stop in the recursion?

Narrowly, for the one-season rating only: round 2 minus round 1 +0.007 (+0.001 to +0.013 over seasons; +0.010 with a learned scale). The production chain gains nothing (-0.001), and SiPM loses with it.

Sample: 18 held-out target seasons

MixedHeld outOne-season round 2 minus round 1: +0.007 (+0.001 to +0.013 (seasons); +0.003 to +0.011 (games))KR05

Does the recursion change the LR02 residual?

No, it widens it: top-60 gap -0.11 (-0.22 to -0.01 over seasons), top-30 -0.09 (-0.25 to +0.06); more non-creating bigs reach the top 30 (82 to 110 rows).

Sample: 4,209 player-seasons, targets 2008-09 to 2025-26

Not supportedHeld outChange in SiPM's top-60 non-creating-big gap: -0.11 per 100 (-0.22 to -0.01 (seasons); -0.21 to -0.01 (players))KR06

Does the recursion change how SiPM grades primary creators' defense, and does next season agree?

No, it lowers the grade further: primary creators' defensive rating minus everyone else's moves -0.29 (-0.32 to -0.27), and their lineups then defend +0.05 better than the new grade says (+0.04 to +0.06).

Sample: 1,073 primary-creator rows of 4,209

Not supportedHeld outChange in creators' defensive grade -0.29; change in their held-out defensive miss +0.05 (-0.32 to -0.27; +0.04 to +0.06 (seasons))KR07

Is the LR02 gap larger in recent seasons, and do season-specific type values shrink it?

No. The top-60 gap is the same in every era (2021-26 minus 2014-21 −0.12, −0.63 to +0.36), and the season-to-season part of the type's lineup miss explains −9% of it (−47 to +20%).

Sample: 1,080 top-60 rows, 229 non-creating-big rows

Not supportedHeld outTop-60 gap explained by season-to-season type value: −9% (−47 to +20% (90%, player bootstrap x team-season bootstrap))CV04

Holding each player's SiPM forecast fixed, do lineups with LR02's non-creating bigs beat or miss the forecast, season by season?

Yes at the lineup level: lineups with last season's non-creating bigs fall short of SiPM's forecast by −0.36 per 100 per such big (−0.59 to −0.15). Removing it closes LR02's top-60 gap (+93% explained, overstated). Player-level LR02 found no type-wide miss (−0.06). Updated 2026-10-15: was −0.57 points per 100 per non-creating big on the floor (18-season mean) (−0.80 to −0.35 (90%, team-season bootstrap)) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 1,314,446 stint sides; 10.9% of player slots unrated (nuisance counts)

SupportedHeld out−0.36 points per 100 per non-creating big on the floor (18-season mean) (−0.59 to −0.15 (90%, team-season bootstrap))CV06

Over ordinary offseasons, does the calendar-day decay over- or under-forget?

Yes: the best clock speed across a healthy offseason gap is 1.25, the opposite of injury absences.

Sample: 5,696 season openers, 1327 players

SupportedIn sample onlyClock speed 1.25; own-prior form 1.40 (1.22 to 1.27; 1.38 to 1.44 (90% player bootstrap))LY10

Do the two approved box-input changes, together, beat production SiPM on the declared held-out test, and do their gains add?

Yes: SiPM with each box stat's memory fitted for next season (FT% and 3P% included) and old games aging at about 0.6 of calendar speed during 41+ game injury absences removes +0.0044 more next-season lineup error than the previous production SiPM (90% +0.0030 to +0.0057), ahead in 14 of 18 held-out seasons. Nearly all of the gain is the memory change; the clock adds +0.0001 (not distinguishable). Adopted 2026-10-07.

Sample: 18 held-out seasons of lineup stints

SupportedHeld outT2 new minus previous SiPM: +0.0044 (memory alone +0.0042, clock alone +0.0001, interaction +0.0001) (+0.0030 to +0.0057 (games); +0.0031 to +0.0058 (home teams); interaction -0.0001 to +0.0002 (90%, 500 paired resamples within target seasons))SP08

With LR02's rows and CV06's lineup data in one model (unshrunk group terms, shrunk players), how large is SiPM's miss on non-creating bigs?

Held on the 2026-10-08 production: -0.42 (-0.72 to -0.14) points per 100 over LR02's rows. On current production (re-run 2026-10-10) it is -0.20 (-0.50 to +0.08), which includes zero. The SiPM reruns of 2026-10-09 (age term, one height standard, rim deterrence) closed about half of the over-forecast; LR02's top-30 version still holds at -0.36 (-0.72 to -0.04).

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

MixedHeld out-0.20 points per 100 (NCB rows minus other LR02 rows, one design) (current production, re-run 2026-10-10; was -0.42) (-0.50 to +0.08 (90%; was -0.72 to -0.14))LR15

Is the non-creating-big miss concentrated at the top of SiPM's board?

No: top-60 NCBs minus other 1,000-minute NCBs −0.17 (−0.65 to +0.20) at the lineup level. LR02's larger top-of-board gap comes from the comparison group: top-60 players who are not NCBs beat their forecasts by +0.34 (+0.12 to +0.59). Updated 2026-10-15: was −0.11 and +0.27 before the 2026-10-09 SiPM reruns.

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

Not supportedClean null-0.17 points per 100 per player on the floor (top-60 NCB minus other surviving NCB) (current production, re-run 2026-10-10; was -0.11) (-0.65 to +0.20 (90%; was -0.56 to +0.26))LR16

Is the NCB miss concentrated in lineups without a star creator, or in NCBs who lost the creator they played with?

No, once each NCB is compared with other role players in the same context: star kept and on the floor −0.22 (−0.64 to +0.17), star kept but sitting −0.37 (−0.84 to +0.16), star gone −0.49 (−1.30 to +0.13), no star −0.52 (−0.92 to −0.15). Unmatched, NCB lineups without a star looked worse; every role player shares that. Updated 2026-10-15: was −0.47, −0.66, −0.58 and −0.75 before the 2026-10-09 SiPM reruns; the first two intervals now include zero (status question already open from the 2026-10-10 audit).

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

Not supportedHeld out-0.37 vs -0.22 (star sitting vs on the floor, NCB minus matched others) (current production, re-run 2026-10-10; was -0.66 vs -0.47) (-0.84 to +0.16 (90%); -0.64 to +0.17 (90%))LR17

Do non-additive lineup features built from last season's box lines account for the NCB lineup miss?

No. Adding each lineup feature (applied to every lineup) leaves the NCB miss in place: M1 explains 6%; M2 explains 5%; M3 explains -2%; M4 explains -11%; all explains -2%. Updated 2026-10-15: was all four together explain -4% of the NCB miss (-25% to 20% (90%)) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

Not supportedHeld outall four together explain -2% of the NCB miss (-39% to 39% (90%))LR18

Does the NCB miss depend on age in the target season?

Lead: NCB minus other survivors of the same age −0.68 (−1.04 to −0.35) at 25 or under, −0.35 at 26-29, −0.11 at 30+. Updated 2026-10-15: was −1.07, −0.31 and −0.38 before the 2026-10-09 SiPM reruns.

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

SupportedIn sample only-0.68 points per 100 per player on the floor (NCB minus others, 25 or under) (current production, re-run 2026-10-10; was -1.07) (-1.04 to -0.35 (90%; was -1.43 to -0.75))LR19

Does a skill-profile age curve improve held-out lineup error and shrink the non-creating-big miss?

Partly. Role plus reliance age curves (AB, adopted 2026-10-08) cut the young-NCB miss from -1.05 to -0.60 per 100 (-0.93 to -0.30 (90%)) and are level on held-out lineups (-0.13 per 1,000, -1.82 to +1.75 (90%)). What is left sits in 2008-13 targets; 2021-25 +0.08 (-0.45 to +0.67 (90%)).

Sample: T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons (1,312 players) next season; 4,365 three-season windows. Profiles 2007-25 (250+ min): NCB 1906, CRE 1441, OBG 407, REST 3938.

MixedHeld out+0.46 per 100 change in the young-NCB gap (AB minus SiPM's single curve; gap -1.05 to -0.60) (+0.44 to +0.48 (90%) paired)LR20

Is the NCB miss in the box layer or the lineup layer of SiPM (LR13's question, as a split)?

Box part above lineup part: NCB minus matched others −0.50 (−0.84 to −0.18); lineup part above box part: −0.15 (−0.50 to +0.11), not distinguishable from zero. Updated 2026-10-15: was −0.69 and −0.38 before the 2026-10-09 SiPM reruns.

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

MixedIn sample only-0.50 vs -0.15 points per 100 (box-led vs lineup-led forecasts) (current production, re-run 2026-10-10; was -0.69 vs -0.38) (-0.84 to -0.18 (90%); -0.50 to +0.11 (90%))LR21

Is CV06's lineup miss the 1,000-minute filter LR02 applies (survivors) rather than a type miss?

No. Players who fall below 1,000 minutes miss their forecasts badly, but NCBs who do miss no more than other players who do (+0.30 (−0.12 to +0.72)). Updated 2026-10-15: was +0.14 before the 2026-10-09 SiPM reruns.

Sample: 4,209 player-seasons (852 NCB, 947 players); 18 seasons of stints, 540 team-season clusters

Not supportedHeld out+0.30 points per 100 per player on the floor (NCB minus other players, both under 1,000 minutes) (current production, re-run 2026-10-10; was +0.14) (-0.12 to +0.72 (90%; was -0.27 to +0.57))LR22

Do profile age terms reduce error against next-season and three-season RAPM for every player?

Yes, on offense: role plus reliance curves (AB) cut next-season error -0.44% and three-season error -1.36%; the shipped pipeline reproduces both.

Sample: T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons (1,312 players) next season; 4,365 three-season windows. Profiles 2007-25 (250+ min): NCB 1906, CRE 1441, OBG 407, REST 3938.

SupportedHeld out-1.36% three-season squared error (AB minus SiPM's single curve); next season -0.44% (-2.15 to -0.61 (90%); next season -0.80 to -0.10 (90%))LR23

Is SiPM's NCB miss confined to young ages?

Calibrated next-season miss on NCBs by age band: -0.63 / -0.41 / -0.38 / -0.34 / -0.27 per 100 (22 or under to 33+), including 26-29.

Sample: T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons (1,312 players) next season; 4,365 three-season windows. Profiles 2007-25 (250+ min): NCB 1906, CRE 1441, OBG 407, REST 3938.

SupportedHeld out-0.38 per 100 at 26-29 (NCB, next season, actual minus calibrated SiPM) (-0.51 to -0.26 (90%))LR24

Does an additive role + reliance curve keep the reliance version's player gains and the role version's young-big cut?

Yes. AB matches LB's player gains (next season -0.09% vs LB, -0.34 to +0.14 (90%)) and LA's young-big cut (gap change vs LB +0.39, vs LA +0.01).

Sample: T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons (1,312 players) next season; 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples.

SupportedHeld out+0.39 per 100 young-NCB gap change, AB minus LB; player error next season -0.09% vs LB (+0.38 to +0.41 (90%); player -0.34 to +0.14 (90%))LR27

Do role x reliance cell terms (shrunk toward role + reliance) beat the additive version?

No. ABX is worse than AB on held-out lineups (-4.87 per 1,000, -7.19 to -2.49 (90%)) and on defense at the player level; shrinkage toward the parents does not save it.

Sample: T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons (1,312 players) next season; 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples.

Not supportedHeld out-4.87 per 1,000 of baseline stint error removed (ABX minus AB, T2) (-7.19 to -2.49 (90%); teams -7.47 to -2.41 (90%))LR28

Do the test's gains survive the production code path?

Yes. With AB wired into dpm_v3 (Revision 6), the shipped forecasts give next-season player error -0.44% (-0.80 to -0.10 (90%)) and three-season -1.36%, matching the test; the switch-off mode reproduces the old SiPM exactly.

Sample: T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons (1,312 players) next season; 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. Per-player shipped vs test forecasts on 9,097 player-seasons.

SupportedHeld out-1.36% three-season squared error, shipped AB minus the previous production SiPM (-2.15 to -0.61 (90%))LR29

Does letting the box part's weights on rebounds, blocks and interior scoring drift with the era (trailing window or trend terms, walk-forward) shrink the 2008-13 young-NCB gap and the 26-29 NCB miss?

No. Drifting box prices barely move SiPM's young-NCB miss: -0.60 now, -0.57 with random-walk prices (change +0.03); the 2008-13 miss stays at -1.59 and the 26-29 miss at -0.34.

Sample: Box: 11,929 player-seasons 2002-25. T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. Drift description: 14,569 player-seasons, 2,859 players, 300 player resamples.

Not supportedHeld out+0.03 per 100 young-NCB gap change, random-walk prices minus SiPM now (BE +0.03) (+0.01 to +0.06 (90%); BE +0.01 to +0.05 (90%))LR30

Do the weights of SiPM's box model (fitted pooled across seasons) differ by 5-season window, and does the pooled price mis-value player types?

Yes, in sample. Assists lost offensive value after 2015, height lost value, offensive rebounds cost less on defense; at the pooled price young NCBs' box line is over-valued by 0.55 per 100 in 2011-15 and 0.52 in 2016-20.

Sample: Box: 11,929 player-seasons 2002-25. T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. Drift description: 14,569 player-seasons, 2,859 players, 300 player resamples.

SupportedIn sample only-0.55 per 100, young NCBs minus others, window price minus lagged pooled price, 2011-15 (-0.87 to -0.25 (90%))LR30a

Does pricing each season's box line at a trailing-window price, shrunk toward the pooled price with a walk-forward chosen pull, beat SiPM's pooled box prices?

No on lineups: held-out lineup error worse (-2.93 per 1,000, -4.36 to -1.33 (90%)), in 2014-25. The box fit improves (-6.7%) and next-season player error improves (-0.39% (-0.67 to -0.11 (90%))), offense only.

Sample: Box: 11,929 player-seasons 2002-25. T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. Drift description: 14,569 player-seasons, 2,859 players, 300 player resamples.

Not supportedHeld out-2.93 per 1,000 of baseline stint error removed (BE minus SiPM now, T2) (-4.36 to -1.33 (90%); teams -4.68 to -1.46 (90%))LR30b

Does a Kalman random walk on the box prices (speed chosen walk-forward) beat SiPM's pooled box prices?

No on lineups: held-out lineup error worse (-3.80 per 1,000, -6.04 to -1.61 (90%)), in 2014-25. The box fit improves (-9.5%) and next-season player error improves (-0.57% (-0.93 to -0.19 (90%))), offense only.

Sample: Box: 11,929 player-seasons 2002-25. T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. Drift description: 14,569 player-seasons, 2,859 players, 300 player resamples.

Not supportedHeld out-3.80 per 1,000 of baseline stint error removed (BR minus SiPM now, T2) (-6.04 to -1.61 (90%); teams -6.31 to -1.41 (90%))LR30c

Does rescaling the 16 rate stats within each season, with pooled prices, beat SiPM's raw per-36 box inputs?

Mixed. Held-out lineups level (+0.95 per 1,000, -0.89 to +2.69 (90%)); next-season player error better (-0.47% (-0.84 to -0.09 (90%))); three seasons level (-0.52% (-1.37 to +0.32 (90%))).

Sample: Box: 11,929 player-seasons 2002-25. T2: 18 held-out target seasons of stints. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. Drift description: 14,569 player-seasons, 2,859 players, 300 player resamples.

MixedHeld out-0.47% next-season player squared error (BS minus SiPM now) (-0.84 to -0.09 (90%); T2 -0.89 to +2.69 (90%) per 1,000)LR30d

Does choosing the drift speed by walk-forward lineup error (or using a fixed-penalty RAPM target) turn the player-level gain into a lineup gain?

No. Tuning the drift speed on lineup error removes most of LR30's lineup loss but not all of it: -0.87 per 1,000 (-2.14 to +0.44 (90%)). Every fixed drift speed above zero is worse on lineups; the player gain shrinks to -0.28% (-0.44 to -0.10 (90%)).

Sample: T2: 18 held-out target seasons of stints; lineup-tuned selection over target seasons 1999..s-1. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. RAPM refit: 30 seasons x 2 penalties.

Not supportedHeld out-0.87 per 1,000 of baseline stint error removed (BRT, speed tuned on lineups, minus SiPM now, T2) (-2.14 to +0.44 (90%))LR30e

Does the 2008-13 young-NCB miss shrink when V3's prior or the minutes-selection of young bigs is modelled?

No. V3's prior carries the 2008-13 miss but changing it (age, a 5-season window, one height standard) moves the 2008-13 gap by at most +0.03; the miss holds whether minutes rose (-1.58) or fell (-1.37). A quarter is the back-test learning late.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

Not supportedHeld out+0.03 per 100, best prior change of the 2008-13 young-NCB gap (VW minus SiPM now; gap -1.60) (+0.02 to +0.04 (90%))LR30f

Does the 2008-13 young-NCB gap shrink when the same model is forecast with weights fitted on every season instead of walk-forward weights?

Yes, a quarter. Refitting SiPM's layer on every season cuts the 2008-13 gap from -1.60 to -1.18; in 1999-2007 it removes the whole miss (-0.78 to -0.03).

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

SupportedIn sample only-0.41 per 100, walk-forward minus final-weight 2008-13 gap (26% of the walk-forward gap, 19% to 39%) (-0.48 to -0.36 (90%))LR30f1

Does adding on-floor opponent rim frequency and accuracy to SiPM's inputs move the 2008-13 young-NCB defensive gap toward zero?

No. A play-by-play rim input (make effect, deterrence, blocks and shooting fouls per opponent rim attempt) added to SiPM's defensive box model moves the 2008-13 young-NCB defensive gap from -0.98 to -1.00. It improves SiPM for everyone instead (LR30f10c).

Sample: Rim shots 1996-97 to 2025-26 placed in lineup stints; tracking check 2013-14 to 2025-26 (6,942 player-seasons); T2 18 held-out seasons, 500 game and 500 team resamples; PL1 1,000 player resamples; young-big measure 400 team-season resamples.

Not supportedHeld out-0.02 per 100, change of the 2008-13 young-NCB defensive gap (RIM minus SiPM now; gap -0.98) (-0.04 to -0.01 (90%))LR30f10

Fitted on each season's own lineups, how far is V3's prior (walk-forward box prices plus carried correction) off for young NCBs?

Yes in the seasons behind 2008-13 forecasts: -1.31 net, -0.80 on defense; V3 keeps -0.55 after that season's lineups. Small or positive in other eras.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

SupportedHeld out-1.31 per 100, prior's young-NCB gap in seasons 2007-08 to 2012-13 (-1.74 to -0.85 (90%))LR30f2

Does the 2008-13 young-NCB gap sit with young bigs whose minutes rose, with dropouts, with a few players or with a lineup context?

No. The 2008-13 miss holds whether minutes rose (-1.58) or fell (-1.37), at any experience and with or without another big; it is spread across 126 players.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

Not supportedHeld out-1.58 per 100, 2008-13 gap among young bigs whose minutes per game rose (fell: -1.37) (-2.35 to -1.06 (90%); fell -2.35 to -0.43 (90%))LR30f3

Does the young-NCB gap vary with league style across seasons, and with team or opponent style within a season?

No. Over 2008-25 the per-season gap tracks every league trend, but with a consistent forecaster over 1999-2025 the link vanishes (three-point share implies -0.18 of an observed -1.06); within-season team style is level.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

Not supportedHeld out-0.18 per 100 implied 2008-13 minus 2014-25 difference from league three-point share (final weights, 1999-2025); observed -1.06 (-0.89 to +0.48 (90%))LR30f4

Which side of the young-NCB comparison moves in 2008-13: young NCBs falling short or young others beating forecasts?

Partly. Against players aged 26-29, in 2008-13 young NCBs fall short by -0.90 (defense -0.78) and other young players come in +0.70 above (offense +0.50). Added after the first run.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

SupportedHeld out+0.70 per 100, young others minus others aged 26-29, 2008-13 (+0.32 to +1.09 (90%))LR30f5

Does SiPM with VH (see page section 4) beat production on held-out next-season lineups (T2)?

Yes: T2 +1.33 per 1,000 (+1.10 to +1.55 (90%)), better, ahead in 15 of 18 seasons. It does not fix the young-big miss.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

SupportedHeld out+1.33 per 1,000 of baseline stint error removed (VH minus SiPM now, T2) (+1.10 to +1.55 (90%))LR30f6

Does SiPM with VA (see page section 4) beat production on held-out next-season lineups (T2)?

Yes: T2 +0.72 per 1,000 (+0.38 to +1.11 (90%)), better, ahead in 15 of 18 seasons. It does not fix the young-big miss.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

SupportedHeld out+0.72 per 1,000 of baseline stint error removed (VA minus SiPM now, T2) (+0.38 to +1.11 (90%))LR30f7

Does SiPM with VAH (see page section 4) beat production on held-out next-season lineups (T2)?

Yes: T2 +2.06 per 1,000 (+1.67 to +2.52 (90%)), better, ahead in 18 of 18 seasons. It does not fix the young-big miss.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

SupportedHeld out+2.06 per 1,000 of baseline stint error removed (VAH minus SiPM now, T2) (+1.67 to +2.52 (90%))LR30f8

Does SiPM with VW (see page section 4) beat production on held-out next-season lineups (T2)?

No: T2 -0.71 per 1,000 (-1.76 to +0.33 (90%)), level, ahead in 6 of 18 seasons. It does not fix the young-big miss.

Sample: Young-big measure: every regular-season stint of 18 target seasons (27 for E1 / A1 / D2), 400 team-season resamples. Young player-seasons 2008-13: 249 NCB, 580 other. T2: 18 held-out target seasons, 500 game and 500 team resamples.

Not supportedClean null-0.71 per 1,000 of baseline stint error removed (VW minus SiPM now, T2) (-1.76 to +0.33 (90%))LR30f9

Does replacing the box target's season-by-season penalty (2,000 to 2014, 2,828 from 2015/2017) with one penalty (2,000) improve SiPM?

Mixed. Lineups better (+0.45 per 1,000 (+0.21 to +0.67 (90%))), all in 2014-25; next-season player error slightly worse (+0.06% (+0.01 to +0.10 (90%))).

Sample: T2: 18 held-out target seasons of stints; lineup-tuned selection over target seasons 1999..s-1. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. RAPM refit: 30 seasons x 2 penalties.

MixedHeld out+0.45 per 1,000 of baseline stint error removed (B0F minus SiPM now, T2) (+0.21 to +0.67 (90%))LR30e1

On a target refitted at one penalty, does the box-fit-tuned drift slow down and stop hurting lineups?

No. On the fixed-penalty target the random walk still picks its fastest speed in 23 of 24 seasons and still hurts lineups (BRF minus B0F -2.32 per 1,000 (-4.49 to -0.26 (90%))).

Sample: T2: 18 held-out target seasons of stints; lineup-tuned selection over target seasons 1999..s-1. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. RAPM refit: 30 seasons x 2 penalties.

Not supportedHeld out-2.32 per 1,000 of baseline stint error removed (BRF minus B0F, T2) (-4.49 to -0.26 (90%))LR30e2

How much does the cross-validated penalty's move from 2,000 to 2,828 shrink 3-season RAPM, and what does it bias?

Yes. In the 10 changed seasons the top 30 players' 3-season RAPM is 0.886 of its one-penalty value; the spread is 1.86 / 1.39 (offense / defense) against 2.08 / 1.57. LR30's 'defensive spread fell' is this. It does not cause the young-big miss.

Sample: 30 seasons, 2 refits each

SupportedIn sample only0.886 = top-30 net 3-season RAPM at the production penalty / at one penalty (2,000), mean over 2015 and 2017-25 (0.881 to 0.893 (range across the 10 seasons; deterministic refit, no sampling interval))LR30e3

Does BSF (16 rate stats z-scored within season, pooled prices, target refitted at one penalty) beat SiPM now?

Yes on players, level on lineups. Next-season player error -0.47% (-0.84 to -0.09 (90%)); lineups +1.49 per 1,000 (-0.34 to +3.27 (90%)); three seasons level. Adoption plan drafted, not applied.

Sample: T2: 18 held-out target seasons of stints; lineup-tuned selection over target seasons 1999..s-1. Player level: 6,458 player-seasons next season, 4,365 three-season windows. Young-big measure: 18 seasons, 400 team-season resamples. RAPM refit: 30 seasons x 2 penalties.

SupportedHeld out-0.47% next-season player squared error (BSF minus SiPM now) (-0.84 to -0.09 (90%); T2 -0.34 to +3.27 (90%) per 1,000)LR30e4

Do young bigs allow more rim points than their blocks, rebounds and height predict, compared with bigs aged 26-29?

Yes, slightly. After the box defensive inputs, young NCBs allow +0.20 more rim points per 100 than NCBs aged 26-29 (2008-13 targets); the forecast miss on defense is about four times larger.

Sample: Rim shots 1996-97 to 2025-26 placed in lineup stints; tracking check 2013-14 to 2025-26 (6,942 player-seasons); T2 18 held-out seasons, 500 game and 500 team resamples; PL1 1,000 player resamples; young-big measure 400 team-season resamples.

SupportedIn sample only+0.20 rim points per 100, young NCB minus NCB 26-29, 2008-13 (+0.10 to +0.29 (90%))LR30f10b

Does adding play-by-play rim inputs to SiPM's defensive box model improve held-out forecasts?

Yes. Deterrence alone (RIMD) improves held-out lineup forecasts by +2.71 per 1,000 and three-season player error by -0.75%; next-season player error is level. All four inputs (RIM) are not better than deterrence alone. Adoption is Griffin's call.

Sample: Rim shots 1996-97 to 2025-26 placed in lineup stints; tracking check 2013-14 to 2025-26 (6,942 player-seasons); T2 18 held-out seasons, 500 game and 500 team resamples; PL1 1,000 player resamples; young-big measure 400 team-season resamples.

SupportedHeld out+2.71 per 1,000 held-out lineup error removed (RIMD minus SiPM now) (+0.78 to +4.78 (90%))LR30f10c

Can a box-to-lineup value model be applied to seasons before lineup data exist?

Fitted on 2011-25 and tested on 1996-2010, the box model explains 0.63 of offensive and 0.38 of defensive 3-season RAPM variance (reverse: 0.56 / 0.32). The reduced 1951-72 version keeps offense (0.62) but loses most of defense (0.24).

Sample: 14562 windows

SupportedHeld outBackcast R2 offense 0.63, defense 0.38 (out-of-time split, no interval)AG01

Does a BPM-style team adjustment improve a box model of 3-season RAPM?

Adding the team's rating gap (team rating minus its players' box values) cuts held-out error of the full box model: offense 0.075, defense 0.274 (squared points per 100).

Sample: 14562 windows

SupportedHeld outMSE gain O 0.075, D 0.274 (block CV, no interval)AG02

Does the box-to-RAPM model over-value a player type, inflating pre-1997 players of that type?

Out of sample, the box model's error does not move with assist rate (-0.00 per SD) or steal rate (-0.00). The 100 seasons most like Stockton's prime show -0.27 (-0.79 to +0.12): a lean, not a finding.

Sample: 14562 windows, 2856 players

Not supportedHeld outAssist-rate slope -0.00, steal-rate slope -0.00 per SD (points per 100) (-0.07 to +0.07; -0.06 to +0.06 (90%, player bootstrap))AG16

Is the box model calibrated at the extremes of the value scale?

The top tenth of box values beat their box value in 3-season RAPM by +0.38 per 100 (+0.13 to +0.61); the bottom tenth by +0.53. Both ends are pulled to the middle.

Sample: 14562 windows, 2856 players

SupportedHeld outTop-decile residual +0.38 points per 100 (+0.13 to +0.61 (90%))AG17

Does a lineup correction learned late in a career (Stockton: ages 34-40) apply to the player's prime?

Fitted only on 2011-26 lineups, a player's correction predicts his 1996-2007 box residual with slope 1.46 (0.93 to 1.96); 1 = full carry-over. Players 33+ when it was learned: 1.51.

Sample: 276 players

SupportedHeld outTransfer slope 1.46 (0.93 to 1.96 (90%, player bootstrap))AG18

Does height predict the box model's error?

Residual rises +0.08 per 100 per SD of height (3.5 inches), +0.01 to +0.15: small, and the all-time box model has no height input.

Sample: 14562 windows, 2856 players

SupportedHeld out+0.08 points per 100 per SD of height (+0.01 to +0.15 (90%))AG19

Is the reduced pre-1973 model biased by player type?

Without steals and blocks, the reduced model's residual rises +0.47 per SD of steal rate and +0.31 per SD of box value, tested on 1996-2026.

Sample: 14562 windows, 2856 players

SupportedHeld out+0.47 per SD of steal rate (+0.40 to +0.53 (90%))AG20

How sensitive is the all-time ranking to a type correction and to the lineup correction's reach?

Not robust: across type corrections and lineup-correction variants his rank runs 2-12; box only 5. Paul runs 6-12. Top-20 membership is stable (17-20 of 20 kept).

Sample: top 20 by peak score

Not supportedIn sample onlyStockton rank range 2-12 across 7 variants (sensitivity, no interval; main 90% rank interval 1-13)AG21

Does production SiPM's box prior have the same top-end calibration gap?

Weaker and U-shaped: 3-season RAPM exceeds SiPM's walk-forward box prior by +0.26 (-0.02 to +0.53) per 100 in the prior's top decile (not distinguishable from zero) and by +0.54 (+0.44 to +0.66) in its bottom decile. The top-end gap sits with heavy-minute players and creators and is explained by exposure (RAPM is shrunk more for low-minute players), not a star effect. The final SiPM forecast under-rates its top decile (+0.19 (+0.02 to +0.34) next season, +0.43 (+0.08 to +0.74) three seasons) whatever the box prior.

Sample: 11,929 player-seasons

MixedHeld outTop box-prior decile, 3-season RAPM minus box value: +0.26 per 100 (-0.02 to +0.53 (90%, 1,000 player resamples))AG22

Do the three changes tested in sandboxes on 2026-10-09, together or in subsets, beat production SiPM on held-out lineups without hurting players?

Yes: SiPM with these changes removes +4.10 more per 1,000 of next-season lineup error than the previous production SiPM (90% +2.20 to +6.06), ahead in 11 of 18 held-out seasons, and changes next-season player squared error by -0.68% (-1.03 to -0.30), a gain. The lineup-rating prior part (age, heights) carries the steady lineup gain; the season-scaled box stats carry the player gain. Adopted 2026-10-09.

Sample: 18 held-out seasons of lineup stints; player tests 6,458 next-season and 4,365 three-season player-seasons; young-big measure 18 seasons

SupportedHeld outT2 new minus previous SiPM: +4.10 per 1,000 of baseline stint error removed (VAH+BSF minus P4) (+2.20 to +6.06 (games); +2.14 to +6.07 (home teams) (90%, 500 paired resamples within target seasons))SP09

Should the single-season RAPM fit, the target of V3's box prior, also move to one penalty?

No: with V3's prior fitted on single-season RAPM at one penalty (2,000) instead of the per-season choice, SiPM's held-out lineup forecast is level or slightly worse (-0.86 per 1,000, -1.65 to +0.02) and its next-season player error is worse (+0.12% (+0.01 to +0.22)). So scripts/rapm.py keeps the cross-validated penalty for single seasons.

Sample: 18 held-out seasons; 6,458 next-season player-seasons

Not supportedHeld out-0.86 per 1,000 of baseline stint error removed (VAH1+BSF minus VAH+BSF, T2) (-1.65 to +0.02 (90%))SP10

Is a box-score assist worth the same in lineup (RAPM) terms in every season?

A smooth trend in the value of creation stats beats a single-era box model out of sample (held-out error -0.029, -0.053 to -0.006). The net assist term rises +0.40 per 100 per unit of league-relative assist rate per decade.

Sample: 14562 windows, 2856 players

SupportedHeld outNet assist-trend term +0.40 per decade (90% +0.26 to +0.56 (player bootstrap))AG23

Did the illegal-defense rules (before 2001-02) change what box creation stats are worth?

A step at 2001-02 fits (net assist interaction -0.38, -0.66 to -0.09), but the 2006-11 period, under the new rules, shows the same assist slope (-0.45) as 1996-2000 (-0.47). The data show a steady drift, not a step at the rule change.

Sample: 2199 old-rule windows

Not supportedHeld out1996-2000 assist residual slope -0.47 vs 2006-11 -0.45 (90% -0.66 to -0.30 and -0.73 to -0.18)AG24

Is the box model less reliable for seasons whose box profile is unlike any 1996-2026 season?

Out of sample, the excess error variance rises from 0 at the median distance (0.872) to 0.75 at distance 2.0 and 2.41 at 3.0 (per 100 squared).

Sample: 14562 windows

SupportedHeld outExcess variance at distance 3.0: 2.41 (90% 0.87 to 3.19)AG25

Does the box model flatter seasons whose profile is unlike modern ones?

Far-out seasons are, on average, under-rated, not over-rated: mean residual 2.3-2.6: +1.25 (+0.54 to +2.20); 2.6-3.0: +1.44 (-0.38 to +2.92).

Sample: 222 far-out windows

Not supportedHeld outMean residual at distance 2.3-2.6: +1.25 (90% +0.54 to +2.20)AG26

Is playoff over- or under-performance (box score) a trait?

Barely: consecutive-postseason correlation +0.05 (+0.01 to +0.09), 1943 pairs. Small playoff samples are shrunk toward the regular season with k = 687 minutes (offense).

Sample: 1943 pairs

MixedIn sample onlyr = +0.05 (90% +0.01 to +0.09)AG27

Do playoff lineups show players who are persistently better or worse in the playoffs than in the regular season?

Pooled over 30 postseasons, cross-validation gains 0.0079% at best; the one-standard-error rule keeps penalty 4,096,000 (top of grid: True). SD of the fitted deviation 0.00 per 100.

Sample: 138141 stint rows, 1666 players

Not supportedHeld outCV gain 0.0079% (5-fold CV over postseasons, 1-SE rule)AG28

How much less certain is a pre-1973 season's value?

The 1951-72 box model's persistent error variance is 0.55 (per 100 squared) above the full model's (+0.45 to +0.67).

Sample: 14562 windows

SupportedHeld outExtra persistent variance 0.55 (90% +0.45 to +0.67)AG29

Does the rim-deterrence input (LR30f10c) still improve SiPM after rerun 2 changed its V3 prior and box inputs?

Yes: adding rim deterrence (opponent rim attempts per 100 possessions with the player on, lineup-adjusted) to the defensive box model removes +2.53 more per 1,000 of next-season lineup error (90% +0.64 to +4.54), ahead in 12 of 18 seasons, and changes three-season player error by -0.59% (-1.02 to -0.14); next-season player error is level. Adopted 2026-10-09 (SiPM rerun 3).

Sample: 18 held-out seasons; 6,458 next-season and 4,365 three-season player-seasons

SupportedHeld outT2 RIMD minus rerun-2 SiPM: +2.53 per 1,000 of baseline stint error removed (+0.64 to +4.54 (games); -0.07 to +5.10 (home teams) (90%, 500 paired resamples))SP11

Does a monotone (isotonic or spline) calibration of the box prior against 3-season RAPM, fitted on earlier seasons only, improve held-out lineups and players?

Mixed: a smooth monotone map (linear spline, slopes kept non-negative) of the box prior improves next-season player error (-0.19% (-0.32 to -0.07)) and three-season error (-0.34% (-0.57 to -0.12)), but held-out lineups are level (-0.44 per 1,000, -1.35 to +0.48). Not adopted: the rule needs lineups and players both better.

Sample: 18 held-out seasons; player tests as SP11

MixedHeld outT2 CALS minus SiPM: -0.44 per 1,000; PL1 -0.19% (-0.32 to -0.07) (T2 -1.35 to +0.48 (90%))SP12

Divergences from consensus 10

Whom does SiPM agree with?

Rank agreement with the model median 0.75 vs the editorial median 0.38; models and editorial lists agree at 0.55.

Sample: 124 players; 8 public sources (4 editorial, 3 model, 1 game)

SupportedIn sample onlySpearman r vs models 0.75, vs editorial 0.38 (models 0.67 to 0.81; editorial 0.24 to 0.51 (90%, player bootstrap))CB02

Are SiPM's divergences unusual for a model?

Mean distance from the other rankings: SiPM 0.58, DARKO 0.46, EPM 0.51, xRAPM 0.71; editorial lists 0.16 to 0.23.

Sample: 124 players; 8 public sources (4 editorial, 3 model, 1 game)

SupportedIn sample onlymean |log2 rank ratio| SiPM 0.58 vs DARKO 0.46, EPM 0.51, xRAPM 0.71 (SiPM 0.51 to 0.65; DARKO 0.40 to 0.53; EPM 0.44 to 0.59; xRAPM 0.63 to 0.81 (90%, player bootstrap))CB03

Which part of SiPM puts consensus top-40 players 20+ places lower than the public consensus?

Against the players SiPM ranks at their consensus spot, the 16 bearish stars give up −1.97 per 100 on defense (−2.40 to −1.52) and are level on offense (+0.02, −0.45 to +0.50). The lineup rating's defense carries most of it (−1.37); luck and gravity adjustments add little. Updated 2026-10-15: was Defense gap to consensus-rank peers −2.00 per 100; offense +0.19 (90% player bootstrap −2.43 to −1.59; −0.32 to +0.76) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 14 bearish stars, 23 other consensus top-40 players, 363 rated players in the universe

SupportedIn sample onlyDefense gap to consensus-rank peers −1.97 per 100; offense +0.02 (90% player bootstrap −2.40 to −1.52; −0.45 to +0.50)SD01

How does the composition of SiPM's bullish divergence list differ from the consensus top 30?

24% of SiPM's 25 bullish divergences are primary creators vs 77% of the consensus top 30 (difference -53 points, -71 to -34); non-creating bigs 40% vs 3%.

Sample: 25 and 30 players; player bootstrap

SupportedIn sample onlyPrimary-creator share -53 points (bullish list minus consensus top 30) (-71 to -34)LR08

Which part of SiPM makes it disagree with public rankings?

Among the 50 largest gaps between SiPM's 2026-27 rank and the pooled consensus median, the lineup rating is the main part for 33; luck adjustment 6, age 6, box score 5, gravity 0.

Sample: 124 players; 8 public sources (4 editorial, 3 model, 1 game)

SupportedIn sample only33 of 50 largest divergences driven by the lineup partCB01

Why does SiPM rank Anthony Edwards 37th for 2026-27 when the pooled consensus has him 7th?

General finding first: SD01 (bearish stars lose on defense). Edwards is one row: SiPM ranks his offense 15th and his defense 246th of 363; with his consensus-rank peers' defense he ranks 9th. Box model and lineup rating agree on both sides. His own SiPM residuals: under-forecast in 4 of 5 seasons, but −1.39 in 2025-26.

Sample: 14 bearish stars, 23 other consensus top-40 players, 363 rated players in the universe

SupportedIn sample onlyRank with peers' defense 9 (actual 37); defense gap to peers −1.96 per 100 (SiPM 80% rank band 16 to 150 (consensus board))SD05

Where does the Wolves' 2025-26 defensive credit go, and is Edwards short-changed?

No. The Wolves' players' ratings add up to +2.36 points per 100 of credit against an actual +2.64; Gobert carries +1.69, Edwards -0.55 (luck-adjusted -0.30).

Sample: Regular-season lineup stints

Not supportedIn sample onlyEdwards on-off defense -3.8 points per 100 (opponent-adjusted; raw -5.7)PE11

When SiPM disagreed most with the preseason consensus, where did the players land?

Backtest on 2025-26: SiPM's 50 largest disagreements with the 4-outlet editorial consensus won a balanced 0.58 of calls on 2025-26 on-court impact (0.47 to 0.70): not distinguishable from a coin flip. On the crowd's own lists a year later the consensus won (0.22, 0.12 to 0.32).

Sample: 125 players in the comparison set; 50 large calls, 40 scored on on-court impact

Not supportedClean null0.57 balanced win share on on-court impact (0.5 = coin flip) (current production, re-run 2026-10-10; was 0.58) (+0.44 to +0.70 (90%; was +0.47 to +0.70))CB07

Are SiPM's disagreements with the crowd better than a public model's?

Backtest on 2025-26: SiPM's balanced win share minus DARKO's preseason disagreements, same rule and consensus: +0.24 (+0.07 to +0.40). DARKO's own disagreements lost to the consensus (0.34, 0.23 to 0.47).

Sample: 50 large calls each; scored SiPM 40, DARKO 38; DARKO as of 2025-10-20 (data through 2025-06-22)

SupportedHeld out+0.23 SiPM minus DARKO balanced win share (current production, re-run 2026-10-10; was +0.24) (+0.04 to +0.39 (90%; was +0.07 to +0.40))CB08

How far does a value-based sustained-peak ranking depart from expert lists?

Rank correlation with the NBA-Ranker seed top 100 0.78; with the published lists' median 0.73.

Sample: 880 players

SupportedIn sample onlySpearman 0.78AG13

Trajectory, aging and breakouts 153

Can a before-the-season forecast of each dimension of a player's season be calibrated?

Forecasting each player's efficiency, usage, creation, minutes, availability and value separately, walk-forward, its 80% ranges cover 78-84% of outcomes. Efficiency R-squared is 0.61, against 0.44 for last season alone.

Sample: About 5,900 player-seasons per dimension, walk-forward

SupportedHeld outEfficiency R-squared 0.62 (last season only 0.44); 80% coverage 78-84% (0.58 to 0.65 (R-squared))TB01

How predictable are breakouts, and when do they happen?

The baseline expected a median 17% of an efficiency breakout and 10% of a value breakout. Value breakouts fall from about 7.2 per 100 seasons at 21 and under to 0.3 at 31 and over.

Sample: 108 efficiency, 197 value breakouts

SupportedIn sample onlyValue breakouts per 100 seasons: 7.2 (21-) to 0.3 (31+) (5.0 to 10.0 (21-))TB05

Which knowable causes mark efficiency and value breakouts?

Young high picks (picks 1-10 in seasons 2-4) are 4.97x over-represented among impact breakouts and 3.61x among value breakouts. A new team is under-represented (0.53x and 0.36x).

Sample: 108 impact and 197 value breakouts

SupportedIn sample onlyYoung high pick lift: impact 4.97, value 3.61; new team lift: impact 0.53, value 0.36 (young high pick share 0.40 (0.32 to 0.48); new team share 0.16 (0.11 to 0.22) (impact) vs base 0.08, 0.296)FM12

Were the biggest usage and creation surprises predictable from team context?

Most of the largest usage surprises had a specific cause known before the season: a star teammate left or was out at the start, the player became the top option, he returned from a lost season, or his team had a top-decile opening. 40 of the top 50 usage surprises had one, against 47% of all player-seasons.

Sample: Walk-forward baseline rows

SupportedIn sample onlyUsage top 50: 40 of 50 with a specific cause (48% of all eligible seasons); creation 37 of 50; promoted-to-top-option lift 3.9 (usage), 6.5 (creation); star teammate left 1.9 and 2.0FM01

Which knowable causes mark usage and creation breakouts?

Among one-season usage breakouts, a star teammate leaving appears 2.15x as often as in all player-seasons, promotion to top option 2.37x and a top-decile opening 2.42x. Creation breakouts show the same pattern. Descriptive tags, not causes.

Sample: 148 usage and 144 creation breakouts

SupportedIn sample onlyLift among usage breakouts: star left 2.16, top option 2.48, top decile opening 2.29; creation: star left 1.97, top option 2.83, top decile opening 2.55 (Usage: star left share 0.37 (0.31 to 0.44); top option share 0.12 (0.08 to 0.17); top decile opening share 0.25 (0.20 to 0.31) vs base 0.172, 0.049, 0.109 (Wilson 90%))FM11

Do richer role-opening inputs shrink the biggest usage and creation surprises?

Better role-opening inputs improve usage and creation forecasts slightly but remove only a few percent of each top surprise; every top-50 surprise stays outside the forecast's 80% range.

Sample: Placebo = inputs permuted within season

SupportedHeld outMSE reduced, established players: usage 1.9%, creation 3.5%; top-50 residual removed net of placebo: usage 1.0%, creation 3.4%; 50 of 50 (usage) and 50 of 50 (creation) still above the 80% range (1.3 to 2.6% (usage); 2.7 to 4.3% (creation))FM09

Does knowing what roles are open on a team help forecast a player's season?

Vacated usage and minutes improve the usage (+2.3%), creation and minutes forecasts, intervals clear of zero, and slightly worsen the efficiency forecast (-0.6%).

Sample: About 5,900 player-seasons per dimension, walk-forward

SupportedHeld outError removed by team context: usage +2.4%, minutes +1.1%, efficiency -0.5% (MSE gain usage 0.171 to 0.304; efficiency -0.021 to -0.005)TB03

Which traits decline with age, and when?

Rim shots, dunks, fast-break shots, blocks and offensive rebounds peak at 21-24 and slide from there; shooting, passing and ball security hold until about 26-28. From 27 to 31 the explosive group falls 0.13 league spreads more than the skill group (-0.17 to -0.08).

Sample: Player-season pairs, 200 player resamples

SupportedIn sample onlyExplosive minus skill change, ages 27-31: -0.18 league spreads (refit, equal pair weights) (-0.26 to -0.08)TA01

Do skills age more slowly than explosive traits after 31?

From 31 to 35 both groups fall by about 0.18 league spreads; the gap is 0.00 (-0.08 to +0.06).

Sample: Player-season pairs, 200 player resamples

SupportedIn sample onlyExplosive minus skill change, ages 31-35: -0.07 (refit, equal pair weights) (-0.17 to +0.03)TA02

Do breakouts on different dimensions happen together?

Usage and creation break out together 12.8 times as often as chance (10.3 to 15.5); efficiency and usage 4.4 times (2.8 to 6.3). Brunson broke out on usage and creation in 2022-23, then on efficiency, usage and value in 2023-24.

Sample: 4,673 seasons eligible on three dimensions

SupportedIn sample onlyLift usage+creation 12.8x; efficiency+usage 4.4x (11.0 to 15.3; 2.7 to 6.2)TB07

Are staircase risers a distinct, identifiable group?

Yes, with no window cap. About 1 in 8 players beat their draft-slot path on efficiency at every draft range; 15% of plateaus are followed by a rise beyond forecast, often on another dimension; early underperformers rarely recover. Rolling outperformance is no more common than chance (TB24).

Sample: 1,135 draft-scored players; 2,184 plateaus; 223 early underperformers

SupportedHeld outDraft outperformers 145 of 1,135 (efficiency); plateau rises 335 of 2,184; early slumps recovered 5%; 744 players in any of ten types (3% to 8% (early recovery))U01

Does the breakout definition catch slow-grind improvers?

Kawhi Leonard and Jimmy Butler never cross the efficiency bar in one season: their efficiency rose 2 to 2.7 points per 100 in several seasons, each below the 3.1 bar. They show up only on usage, creation, minutes and value.

SupportedIn sample onlyKawhi and Butler: several rises of 2.0-2.7 vs the 3.1 barTB17

After a player plateaus, how often does he rise again (climber type 2)?

Of 2,184 plateaus, 336 were followed by a rise beyond forecast (15%); in 249 the rise was on another dimension (e.g. Butler's usage after 2012-14). The chance falls from 42% (38-46%) for plateaus ending at 23 and under to 4% (3-5%) at 30+.

Sample: 2,184 plateaus, 1,173 players

SupportedHeld out336 of 2,184 plateaus rose later; 249 on another dimension; 42% at 23- vs 4% at 30+ (38% to 46% (23-); 3% to 5% (30+))TB22

How often do players beat what their draft slot implied (climber type 1)?

Draft outperformers (above the draft model's 80% range in 2+ seasons from year three): 145 of 1,135 on efficiency (13%). Late picks and top picks outperform at similar rates because the expectation is set by slot.

Sample: 1,135 players (efficiency)

SupportedHeld outEfficiency 145 of 1,135 (13%); value 13%, usage 17%, creation 14%, defense 16%TB21

How often do players rise beyond the forecast made after two seasons (climber type 5)?

351 of 1,509 players rose beyond the forecast made after their first two NBA seasons: undrafted 15%, second round 20%, first round 26% (Ingles, VanVleet, Covington). Descriptive.

Sample: 1,509 players

SupportedIn sample only361 of 1,509; undrafted 17%, 2nd round 22%, 1st round 26%TB30

How common is a late peak (climber type 7)?

58 of 361 good players (16%) set their career-best impact (+2.0 or better) at 30 or older (Jokic, Stockton, Kawhi, Olajuwon, Malone). Descriptive.

Sample: 361 players

SupportedIn sample only58 of 361 good players (16%); value 71TB26

Do climbs follow a change of team (climber type 6)?

151 of 336 plateau rises (45%) came on a new team: 74 talent climbs and 77 role unlocked (e.g. role: Millsap; talent: Pau Gasol, Korver). Without a move: 110 and 75. Descriptive.

Sample: 336 rises

SupportedIn sample only149 of 335 plateau rises after a move (44%)TB25

Do early-career underperformers catch up (climber type 3)?

Of 223 players below the draft model's 25th percentile in 2+ of their first 3 seasons, 12 recovered (5%, 3 to 8%); among those who kept playing, 11%.

Sample: 223 players

SupportedHeld out12 of 223 recovered (5%) (3% to 8%)TB23

Do mid-career skill jumps lead to climbs (climber type 8)?

Of 378 skill jumps at 24 or older, 56 led to a climb within two seasons: 18% of three-point-volume jumps and 8% of FT% jumps. Brook Lopez's 2016-17 three-point jump is found, but his impact did not climb beyond forecast.

Sample: 378 skill jumps

Not supportedIn sample only58 of 378 skill jumps led to a climb; three-point jumps 20%, FT% jumps 6%TB27

Is rolling outperformance a real type (climber type 4)?

Not above chance: runs of seasons above the one-season forecast happen as often as when each player's seasons are shuffled (efficiency 32 vs 39 by chance). The baseline already absorbs persistent outperformance.

Not supportedClean nullEfficiency / usage / creation / value: 38 / 51 / 83 / 65 vs 42 / 53 / 74 / 65 by chanceTB24

Do breakouts last?

Under the design's talent definition, 106 player-seasons broke out from 1997-98 to 2025-26 (about 3.7 a season), and 58 of the 106 held up the next season. A quick read-only look, no interval.

Sample: 106 breakouts

SupportedIn sample only58 of 106 held upTD01

Does the precedent lookup add forecasting information beyond age?

Held out, the share of a player's 40 nearest historical precedents who broke out next season ranks players no better than the breakout rate for his age band (AUC 0.701 vs 0.708). The lookup is a reading aid, not a better forecast.

Sample: 7,356 queries, 1,358 players; breakout rate 6.7%

Not supportedClean nullHeld-out AUC 0.701 (precedents) vs 0.708 (age band); Brier 0.0606 vs 0.0609 (AUC difference -0.0251 to 0.0118; Brier gain -0.000427 to 0.000963 (90% player bootstrap))FM10

Used as an input rather than a replacement, does the precedent share help?

Added to age in a walk-forward logistic, the fitted precedent share raises held-out AUC by +0.018 for next-season breakouts and +0.065 for a breakout or climb within three seasons; it still adds on top of age plus the baseline.

Sample: 6,365 and 5,040 queries

SupportedHeld out+0.023 AUC (one season), +0.066 (three seasons) over age; +0.013 / +0.049 over age + baseline (one season +0.016 to +0.030; three seasons +0.053 to +0.079; over age + baseline +0.007 to +0.019 / +0.038 to +0.060 (90% player bootstrap; Brier gains also above zero))PF02

Do learned similarity weights make the precedent breakout share a better forecast than age alone?

It does not. Weights learned walk-forward to predict breakouts, climbs and value changes over the next 1-3 seasons give a held-out breakout AUC of 0.695 vs 0.708 for age alone; no fitted variant beats age (best 0.711).

Sample: 7,356 queries, 1,358 players; breakout rate 6.7%

Not supportedClean nullHeld-out AUC 0.706 (fitted) vs 0.708 (age band); Brier 0.06060 vs 0.06085 (AUC difference -0.017 to +0.014; Brier gain -0.00047 to +0.00087 (90% player bootstrap, 500))U29

Does the fitted lookup beat the trajectory baseline at ranking who breaks out next season?

Against the declared baseline comparator (forecast turned into a probability with its spread, AUC 0.580) the fitted lookup wins, but that comparator is weak. Against a fairer baseline score added after the first run (logistic on the forecast gaps, AUC 0.697) it ties.

Sample: 7,356 queries, 1,358 players; breakout rate 6.7%

Not supportedClean nullAUC 0.706 vs 0.697 (fair baseline); vs declared comparator +0.125 (vs fair baseline -0.011 to +0.032; vs declared +0.103 to +0.149 (90% player bootstrap))PF01

Can the lookup replace the baseline for value forecasts?

It does not. Predicting next season's change from the precedents' changes beats age alone but falls short of the baseline forecast (R² imp 0.14 vs 0.18, usg 0.11 vs 0.23, cre_pct 0.08 vs 0.18, mpg 0.23 vs 0.27, value 0.13 vs 0.18).

Sample: 4,720 queries (usage)

Not supportedHeld outusage R² 0.11 (fitted lookup) vs 0.23 (baseline) (fitted minus baseline -0.135 to -0.101 (variance units, 90% player bootstrap))PF04

Does the lookup forecast development over 1-3 seasons better than age?

On its own, the fitted lookup's share of precedents with a breakout or climber event within three seasons gives held-out AUC 0.724 vs 0.663 for age; the current lookup gives 0.720. Updated 2026-10-15: was AUC 0.725 vs 0.664 (difference +0.047 to +0.075 (90% player bootstrap, 200)) before the 2026-10-05/07 re-runs; numbers refreshed from the current output.

Sample: 6,721 queries

SupportedHeld outAUC 0.724 vs 0.663 (difference +0.047 to +0.075 (90% player bootstrap, 200))PF03

How much of a young high pick's growth was expected from draft day?

For a top-3 pick, the baseline expected a median 54% of his breakout-sized minutes rise; for picks 31+, 30%. For efficiency and value, even top picks' breakouts were mostly unforeseen. Added after the first results.

Sample: About 5,900 player-seasons per dimension, walk-forward

SupportedIn sample onlyMedian share of a minutes breakout expected: 52% (picks 1-3) vs 31% (31+)TB04

Can anyone predict a late (25+) jump in three-point volume (the Brook Lopez question)?

No. Lasting jumps are rare (111 of 4,025 seasons at 25+, 2.8%), and nothing measured in advance predicts them: out-of-sample AUC 0.56 vs 0.54 for season and prior volume alone.

Sample: 4,025 seasons

Not supportedClean nullLasting jumps are rare (111 of 4,025 seasons at 25+, 2.8%), and nothing measured in advance predicts themT02

Is a rookie's second-half jump real?

Mostly not: about 85% noise. Splitting his games odd and even produces almost the same spread.

Not supportedIn sample onlyabout 85% noiseT22

Where does a departing player's share of plays go over a season?

Yes. Of the share of team plays that departing players leave, arrivals take 87.1% and the players who stay take 12.9% (11.6 to 14.2). Pre-season veteran arrivals take 47.4%, rookies 23.1%, in-season arrivals 16.6%.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

SupportedIn sample onlystayers 12.9% of departed plays; arrivals 87.1% (stayers 11.6 to 14.2 (90%, team-season bootstrap))UA16

When stayers' share of team plays rises after departures, is it a bigger role per game or more games?

Of departed plays, stayers' role growth (share of plays in the games they play) is 4.3% and their availability growth (playing more of the team's games) 8.6%.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

SupportedIn sample onlyrole part 4.3%, availability part 8.6% of departed plays (role 3.2 to 5.3; availability 7.4 to 9.9)UD01

When a high-usage player leaves, does his share go to the remaining players the way it does on nights he sits?

No. Held out on 2013-14 to 2025-26 departures, splitting the opening with the game-level model changes season forecast error 0.4% vs no allocation, and ranks within teams worse than the proportional split. Stayers pick up only 11% of a departure's share combined. Updated 2026-10-15: was season error 0.4% (game-level split) and -0.1% (proportional) vs drift only (-1.1 to 2.0%; -1.4 to 1.2%; stayers' combined share of the opening 8 to 13%) before the 2026-10-05 game-order fix re-run; numbers refreshed from the current output.

Sample: 1,991 test rows on 217 team-seasons with net opening 10+ points (2013-14 on)

Not supportedHeld outseason error 0.4% (game-level split) and -0.1% (proportional) vs drift only (-1.3 to 2.1%; -1.5 to 1.3%; stayers' combined share of the opening 8 to 14%)UA11

Does a team play faster or slower (more or fewer plays per game) to absorb a departure?

No. In per-game terms the change in the team's total plays covers -0.7% of departed plays; arrivals 87.3%, stayers 13.4%.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

Not supportedClean nullteam-total term -0.7% of departed plays per game (-1.1 to -0.3)UD02

Does a team-level replacement-plan signal predict how much stayers absorb on held-out seasons?

Yes. Adding the arrivals' predicted share (from prior shares and draft slots) cuts the error in predicting the stayers' role growth by 8.4% for plays and 11.0% for created baskets on 2013-14 to 2025-26.

Sample: 390 held-out team-seasons

SupportedHeld outMSE change -8.4% vs opening only (plays) (-13.7 to -2.5% (90%, team-season bootstrap))UD10

Do stayers absorb more when the arrivals are weak relative to the opening?

Yes. When the arrivals' predicted share covers little of the opening (bottom third), stayers' role growth is 10.9% of departed plays; when it covers the opening (top third), -3.5%.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

SupportedIn sample onlylow minus high coverage: 14.4% of departed plays (stayers' role part) (11.9 to 17.0)UD03

Do stayers absorb more when the arrivals are few?

Weakly. With 0-3 pre-season arrivals stayers' role growth is 7.3% of departed plays; with 6+, 3.0%.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

SupportedIn sample onlyfew minus many arrivals: 4.3% (0.7 to 7.9)UD04

Does the replacement-plan signal improve the hm baseline's season creation % forecast?

Yes, slightly. On established players (1,000+ minutes), adding the uncovered opening, heir and top-option-gone terms to the history-mean baseline cuts held-out error by 1.6%; the plain opening term does less.

Sample: 5,914 established rows, 9,850 all rows

SupportedHeld outMSE 1.6% lower (established rows) (1.08 to 2.20% (90%, player bootstrap); beyond the plain opening 0.72 to 1.74%)UD13

Does the replacement-plan signal improve the hm baseline's season usage % forecast?

Yes, slightly. On established players (1,000+ minutes), adding the uncovered opening, heir and top-option-gone terms to the history-mean baseline cuts held-out error by 0.8%; the plain opening term does less.

Sample: 5,914 established rows, 9,850 all rows

SupportedHeld outMSE 0.8% lower (established rows) (0.38 to 1.22% (90%, player bootstrap); beyond the plain opening 0.12 to 0.90%)UD12

Does team context predict which stayer gains, on held-out seasons?

No. At the player level the full model (replacement plan, heir, second option, top option gone) changes held-out error -1.1% for plays and -2.2% for creation, not distinguishable from zero; it picks the top absorber no better than the simple model.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

Not supportedClean nullMSE change -1.1% vs drift + opening (plays) (-3.3 to 1.1%)UD11

How much does a role opening add to a player's usage beyond the forecast?

Only top-decile openings push usage above the forecast (+0.41, 0.23 to 0.59) and creation (+0.66). Sharing an opening in proportion to current usage over-predicts badly (usage MSE 6.19 to 47.7).

SupportedIn sample onlyTop-decile opening: usage +0.46, creation +0.77 (usage 0.28 to 0.63; creation 0.49 to 1.11 (90%))FM04

Do stayers absorb more when the departure is a star (top-1 usage) rather than a role player?

Yes. When the top option (highest role share) is not on the opening roster, stayers' role growth is 8.6% of departed plays, vs 2.4% otherwise.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

SupportedIn sample onlydifference 6.2% of departed plays (4.0 to 8.4)UD05

Do Griffin's examples of stayers who exploded fit a describable pattern, or are they outliers?

Partly. Brown 2025-26, Westbrook 2016-17 and Harden 2024-25 are all heirs (the top claim after the top option left); heirs are 3.68x over-represented among the 50 largest usage jumps. But 60% of those jumps had no ex ante opening flag, and the model predicted almost none of each example's jump (z 2.09, 3.17, 2.54). Kobe 2005-06 sits only in the large-opening cell, with no top-option departure (his 2004-05 jump, after the Shaq trade, is in the 'top option stays, co-star left' cell).

Sample: 4,232 stayer rows; top 50 role-share gains

MixedIn sample onlyheir share of the top 50 usage jumps 8% vs 2.2% of stayers (lift 3.68) (Wilson 90% 3.6 to 16.7%)UD09

Does the stayer who becomes the top remaining option grab more of the plays?

Mixed. Heirs gain 0.9 points of team plays on average vs 0.1, but the model's heir term is not distinguishable from zero.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

MixedIn sample onlyheir mean gain +0.92 points of role share; M2 opening x heir +0.061 (mean 0.38 to 1.41 points; M2 -0.005 to 0.128)UD08

Do stayers absorb a lot when they are already the second option?

No. When the top option leaves, the former second option gains 0.5 points of team plays per game played on average, no more than the third (0.9) or lower options (0.8).

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

Not supportedIn sample onlysecond option, top option gone: +0.46 points of role share (-0.10 to 1.00 points (90%, team-season bootstrap); M2 opening x second +0.000 (-0.026 to 0.027))UD06

Do players whose games rest on skill (Durant, Curry) decline less than explosive players of the same age and level?

Not supported among players who keep playing: per SD of reliance on explosiveness, the yearly impact change is +0.002 points per 100 (-0.037 to +0.050). Among stars the gap leans Griffin's way (-0.11 a year, -0.30 to +0.07), but the interval reaches zero. Updated 2026-10-15: was Impact change per SD of explosive reliance: -0.006 points per 100 per year (-0.043 to +0.037) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 1,127 season pairs

Not supportedClean nullImpact change per SD of explosive reliance: +0.002 points per 100 per year (-0.037 to +0.050)TA03

Does SLAP-lite (frame plus combine athleticism) predict slower aging?

No reliable difference: a slower decline after 28 shows in a simple model, but not once each band and role gets its own age curve. Headline withdrawn in the critic round.

Not supportedClean nulla slower decline after 28 shows in a simple model, but not once each band and role gets its own age curveT24

Does explosive reliance predict exits rather than decline among stayers?

58% of explosive-reliant players are gone by 33 against 50% of skill-reliant ones. Counting leavers as replacement level, each SD of explosive reliance costs -0.103 points of impact at 33 (-0.190 to -0.011). The evidence for Griffin's idea sits in who leaves, not how fast stayers decline. Updated 2026-10-15: was Impact at 33 per SD of explosive reliance, leavers at replacement: -0.092 (-0.174 to -0.004) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 696 players

SupportedIn sample onlyImpact at 33 per SD of explosive reliance, leavers at replacement: -0.103 (-0.190 to -0.011)TA04

Until a veteran shows tangible decline, should we assume less decline?

Players 31+ with no decline signal did not beat the age curve the next year; they did slightly worse than the rest (difference -0.101, -0.202 to -0.009). Decline signals did not improve forecasts either. Updated 2026-10-15: was No-signal minus rest, next-season result vs age curve: -0.049 (-0.139 to +0.038) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 222 no-signal vs 578 other seasons at 31+

Not supportedClean nullNo-signal minus rest, next-season result vs age curve: -0.101 (-0.202 to -0.009)TA05

Does a count of high-level seasons since 30 help aging forecasts?

The only signal pointing Griffin's way: +0.54% of error removed (-0.02 to +1.16), not distinguishable from zero. Players with 3+ such seasons beat the curve by +0.11 (descriptive). Not yet tested inside SiPM (Option C). Updated 2026-10-15: was Error removed by the Lindy count, ages 30+: +0.59% (-0.02 to +1.26) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 114 seasons with 3+ high-level seasons

MixedClean nullError removed by the Lindy count, ages 30+: +0.54% (-0.02 to +1.16)TA07

Do season-end decline signals sharpen aging forecasts?

Adding the signals to the age curve removes -0.70% of error at 30+ (-1.36 to -0.07): no gain; the signals make the forecast slightly worse. A drop in true shooting predicts a slightly better next season, because it is mostly luck. Updated 2026-10-15: was Error removed by decline signals, ages 30+: -0.86% (-2.23 to +0.31) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: Walk-forward

Not supportedClean nullError removed by decline signals, ages 30+: -0.70% (-1.36 to -0.07)TA06

When does each skill peak, and how fast does it fall?

Blocks, offensive rebounds and steals peak by 23; overall value (BPM) at 26; assists 27; 3P%, FT%, 3PA at 28 or later. After 31 the steepest falls are shot volume, free throws and true shooting.

SupportedIn sample onlyBlocks, offensive rebounds and steals peak by 23T03

Does the age drift of the latent level depend on career stage and pre-NBA years, not only on age?

At about 23, a second-year player (entered at 22.5) is expected to gain +0.30 impact per 100 next season; a fifth-year player of the same age is flat (0.00). Growth stops around 23-26 for early entrants and decline starts near 27.

Sample: Full-sample state-space fit

SupportedIn sample onlyEfficiency drift at ~23: 2nd-year +0.30 vs 5th-year 0.00 per season; at 30: -0.25; at 35: -0.36 (0.22 to 0.38 (2nd-year); -0.06 to 0.05 (5th-year); 90% jackknife over 10 player groups)SS07

Does composition-adjusted foul-drawing skill fall less with age than raw FT rate?

About half. From 24 to 35, shooting fouls per attempt fall 30% of the league rate for the typical player, and shot mix accounts for 47% of that. Composition dominates at 24-27 (about 90%); at 31-35 the decline is mostly lost foul drawing (FT05).

Sample: 200 player bootstraps

SupportedIn sample onlyComposition share of the 24-35 decline: 47% (player-average); 58% (pooled, declared) (0.41 to 0.54 (player-average); 0.46 to 0.71 (pooled))FT02

Does FT-based explosiveness still fall with age once shot mix is fixed?

Mix-adjusted foul drawing peaks at 27 (raw FT rate at 24) and falls 0.33 league spreads from 31 to 35 (-0.44 to -0.24), about as much as raw FT rate (-0.30). So the late decline is not composition (declared H3b not supported).

Sample: 200 player bootstraps

SupportedIn sample onlySkill change 31-35: -0.33 spreads; peak age 27; skill minus raw FT rate 31-35: -0.03 (-0.44 to -0.24; peak 24 to 28; -0.11 to +0.04)FT05

Does the make/miss mix change the free-throw count with age?

From 31 to 35, and-ones per make fall 0.31 league spreads (-0.47 to -0.15), so free throws per shooting foul rise +0.22 (0.05 to 0.46). Raw FT rate hides part of the finishing decline. Updated 2026-10-15: was And-ones per make 31-35: -0.31 spreads; FTs per shooting foul +0.22 (-0.47 to -0.15; 0.04 to 0.46) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

SupportedIn sample onlyAnd-ones per make 31-35: -0.31 spreads; FTs per shooting foul +0.22 (-0.47 to -0.15; 0.05 to 0.46)FT06

Are persistently missed players missed mainly early (draft) or late (aging)?

Not supported. Both top-20 groups miss by about the same amount at every age band and career stage until 34+; league-wide no age band or career stage differs from zero. Individuals differ (Hill best after 30, Rondo worst after 30).

Sample: 4,311 player-seasons, 947 players

Not supportedIn sample onlyEveryone, age 34+: -0.05 (-0.19 to +0.09)PM09

Does being fast for one's size predict beating the model (the size-speed frontier)?

Weakly: peak speed for size vs the factor model's miss, rank correlation 0.10 (0.002 to 0.20), just above zero; speed with the ball alone is not significant. LeBron, Giannis and Durant are fastest with the ball for their size. Updated 2026-10-15: was 0.11 (0.02 to 0.20) before the 2026-10-01 re-run chain.

Sample: 328 players

SupportedIn sample onlypeak speed for size vs the factor model's miss, rank correlation 0.10 (0.002 to 0.20)E26

Does the baseline handle injury seasons well (climber type 9)?

Not on all returners. After 41+ missed games, return-season impact runs -0.69 per 100 below the forecast and lands above the 80% range 7.2% of the time (10% expected). The 16-18% counted only returners with 1,000+ minutes, a condition on the outcome.

Sample: 2,217 returns

Not supportedHeld outAll 2,217 return seasons: mean residual -0.69, above range 7.2% (-0.77 to -0.62; above 6.3% to 8.1%)TB28

Is there an injury over-penalty once playing time is held equal?

Yes, slightly. Holding realized minutes equal, first seasons after 41+ missed games beat the impact forecast by +0.18 per 100. Neither injury block removes it (M1 +0.19, M2 +0.20).

Sample: 2,217 return seasons

SupportedHeld out+0.18 impact per 100 (minutes-matched) (+0.09 to +0.27)IE07

Does weighting earlier seasons fix the over-penalty for injury-shortened seasons (TB28)?

After a season with 41+ missed games, the old baseline saw impact above its 80% range in 18.2% of return seasons (10% expected). With the history mean it is 16.2%: closer, still above 10%.

Sample: 587 return seasons with impact

MixedHeld outImpact above the 80% range in first seasons back: 18.2% (old baseline) to 16.0% (history mean + M1) of 587 (10% expected); value 8.3% (see trajectory_climbers_more.json type9)TB32

Does a model of the baseline's miss on knowable inputs (cause of the short season, last healthy level, age, injury type, team need) beat the baseline on returning players?

Yes. Held out 2009-10 to 2025-26, squared error vs the baseline with M1: gp82 9.4% lower (6.4% to 12.5%); mpg 12.1% lower (8.4% to 16.1%); min82 11.2% lower (7.4% to 15.8%).

Sample: 1,634 rows (1,520 short, 114 gap), 826 players; 1,032 held out

SupportedHeld outgp82 9.4% lower squared error; mpg 12.1% lower squared error; min82 11.2% lower squared error (gp82 6.4% to 12.5%; mpg 8.4% to 16.1%; min82 7.4% to 15.8% (90% paired player bootstrap))RP01

Does a model of the baseline's miss on knowable inputs (cause of the short season, last healthy level, age, injury type, team need) beat the baseline on returning players?

Yes. Held out 2009-10 to 2025-26, squared error vs the baseline with M1: value 5.1% lower (2.8% to 7.5%); imp 4.1% lower (2.0% to 6.2%).

Sample: 1,634 rows (1,520 short, 114 gap), 826 players; 1,032 held out

SupportedHeld outvalue 5.1% lower squared error; imp 4.1% lower squared error (value 2.8% to 7.5%; imp 2.0% to 6.2% (90% paired player bootstrap))RP02

Does a model of the baseline's miss on knowable inputs (cause of the short season, last healthy level, age, injury type, team need) beat the baseline on returning players?

No. Held out 2009-10 to 2025-26, squared error vs the baseline with M1: usg 1.4% lower (-0.2% to 3.2%); cre_pct 0.6% lower (-1.3% to 2.4%).

Sample: 1,634 rows (1,520 short, 114 gap), 826 players; 1,032 held out

Not supportedClean nullusg 1.4% lower squared error; cre_pct 0.6% lower squared error (usg -0.2% to 3.2%; cre_pct -1.3% to 2.4% (90% paired player bootstrap))RP03

Does a typed injury block forecast next season better than games missed alone?

Splitting games missed into injury and other absences, with a major-injury flag, an injury still running at season's end and a major injury two seasons back, cuts held-out error for role minutes (1.5%), games (3.6%), value (1.1%) and impact (0.7%); not usage or creation.

Sample: 9,850 evaluation rows; 1,043 after a major injury

SupportedHeld outKnowable inputs (adopted): all-row MSE cut games 2.3%, value 0.7%, impact 0.4% (as tested with next-season inputs: 3.7%, 1.2%, 0.7%) (games 1.6% to 3.0%; value 0.2% to 1.2%; impact 0.2% to 0.7% (90% paired player bootstrap))IE01

Which granularity of injury category is worth carrying in a forecast?

Walk-forward: subcategory x type cuts the return-year impact error by 2.8%; location alone does not help significantly; no granularity helps games. Griffin's four groups cut minutes error 3.1% and value 2.1%.

Sample: 585 events (impact), 683 (games)

MixedHeld outImpact error cut, subcategory x type: 2.8% (0.4% to 5.4% (90% paired player bootstrap))IT10

Do injury types add forecasting power beyond an overall injury effect?

No. Adding subtype terms to the overall block (M2 vs M1) improves no dimension on major-injury rows and worsens usage and creation. The Achilles term moves Achilles rows' impact residual from -1.23 to +0.07, on about 30-40 cases.

Sample: 1,043 rows (Achilles 30, ACL 64)

Not supportedHeld outM2 vs M1 MSE change on major-injury rows, impact (-0.079 to +0.038)IE02

For gap returners (Klay Thompson 2021-22, Durant 2020-21), does propagating the latent level through the gap beat persistence?

The baseline cannot forecast a player with no minutes last season. A state-space model, which carries the hidden level through the gap with the age drift, beats "his last full season" on usage, minutes, games, value and defense (52 returns).

Sample: 52 returns (usage), 82 (games)

SupportedHeld outRMSE, last full season to state-space: usage 3.41 to 2.95; minutes per game 10.89 to 8.39; games 40.98 to 30.30; value 110.02 to 71.93; defense 0.76 to 0.62 (usage -0.84 to -0.04; minutes per game -3.32 to -1.64; games -12.94 to -8.76; value -48.04 to -27.10; defense -0.24 to -0.06 (RMSE change, 90% player bootstrap))SS05

For gap returners, does composing value from state-space efficiency, minutes and games beat 'his last full season'?

Yes. RMSE 69.1 vs 110.0 points of value. It is no better than the state-space value forecast itself (-7.8 to 2.1).

Sample: 82 seasons

SupportedHeld outRMSE 110.0 (last full season) to 69.1 (composed) (RMSE difference -50.6 to -31.1 (90% player bootstrap))VP03

When a star's last season was short (Curry 2019-20, 5 games), does the state-space model forecast his return better?

Partly. For stars back from a short season (43 seasons) the state-space forecast still has lower RMSE than the current baseline (usage 3.87 to 3.17, creation 5.11 to 4.51), but none of the three intervals is below zero: not distinguishable from zero. Against baseline Revision 2 all three were. Value is not fixed.

Sample: 43 seasons, 38 players (usage)

MixedHeld outRMSE, stars returning, baseline to state-space: usage 3.87 to 3.17; creation 5.11 to 4.51; minutes per game 4.53 to 4.09 (RMSE change vs baseline: usage -1.47 to 0.04; creation -1.28 to 0.09; minutes per game -0.85 to 0.02 (90% player bootstrap))SS04

Does (efficiency + 2) x minutes per game x games x pace, each from the state-space model, forecast returning stars' value better?

Not supported. Value built from its parts (efficiency + 2) x minutes per game x games x pace misses returning stars by more than the direct forecast: RMSE 119.6 vs 110.8. With state-space efficiency and minutes it ties (112.1).

Sample: 52 seasons, 42 players

Not supportedHeld outRMSE, returning stars, direct production forecast to composed: 112.2 to 117.5 (RMSE difference 1.6 to 9.4 (90% player bootstrap); state-space parts -6.8 to 2.0)SS10

Which part of value (efficiency, minutes, games, pace) carries the returning-star miss?

Yes. The spread of the miss (SD of log actual/forecast) is 0.74 for games, 0.44 for efficiency, 0.19 for minutes per game and 0.02 for pace.

Sample: 48 seasons

SupportedIn sample onlySD of log actual/forecast: games 0.76, efficiency 0.45, minutes 0.19VP02

Are the misses on a returning star's efficiency, minutes and games correlated?

Yes. When a returning star beats his forecast on games he tends to beat it on minutes (+0.53) and efficiency (+0.43). So the product of three cautious part forecasts is too low.

Sample: 48 seasons

SupportedIn sample onlyCorrelation of log actual/forecast: minutes~games +0.52; efficiency~games +0.43 (minutes~games 0.34 to 0.74; efficiency~games 0.24 to 0.59 (90% player bootstrap))VP01

Can injury-driven athleticism loss be seen in public data?

Partly. Against same-age uninjured players, dunks per 36 fall in the injury season (-0.050; Achilles year 1 -0.123); rim-attempt rate does not move; free-throw rate is lower by year 2 (-0.008).

Sample: 1,892 injury events (926 major, 21+ games), 932 players

MixedHeld outDunks per 36, injury season -0.051; FT rate year 2 -0.008 (-0.069 to -0.032; -0.014 to -0.001)U14

Compared with players who did not break out, did efficiency rise earlier for players who broke out on usage or creation?

Before a usage breakout, efficiency had already risen 20+ percentile points and held in 38% of cases vs 17% of eligible non-breakouts. Before creation breakouts: 34% vs 18%.

Sample: 10,228 player-seasons, 1,820 players

SupportedIn sample only+20.3 points (usage breakouts); +16.2 (creation) (+11.3 to +29.1; +7.0 to +25.6)TS03

Within rise episodes, does efficiency lead usage?

Where both rose, efficiency crossed first in 38% of 128 episodes (chance 34%); usage first in 23% (chance 31%). Efficiency first is inside the chance band; usage first is at its low edge.

Sample: 10,228 player-seasons, 1,820 players

Not supportedClean nullEfficiency first 38% vs chance 33% (31% to 46%; chance band 27% to 40%)TS02

Do minutes (role) move before usage?

Minutes per game rose early before 44% of usage breakouts vs 18% of controls. Over all players, a minutes rise with usage flat raises next season's chance of a usage rise from 9% to 18%.

Sample: 10,228 player-seasons, 1,820 players

SupportedIn sample only+25.6 points early-move share (usage breakouts); +8.8 points next-season usage rise (+17.7 to +36.0; +6.7 to +11.2)TS04

When usage and creation both rise, which moves first?

In 100 rise episodes where both rose, usage and creation crossed in the same season 60% of the time; random timing gives 35%. Usage first (19%) and creation first (21%) are both below chance.

Sample: 10,228 player-seasons, 1,820 players

SupportedIn sample only60% same season vs 36% by chance (51% to 67% (90%, player bootstrap); chance band 28% to 43%)TS01

Does a usage rank far below efficiency close from below?

At the same usage quintile, players whose efficiency ranks 2+ quintiles higher are no more likely to gain a usage quintile (-0.2 points). They are more likely to gain minutes (+9.3).

Sample: 10,228 player-seasons, 1,820 players

Not supportedClean null-0.2 points (-4.1 to +3.2)TS06

Does a usage rank far above efficiency close from above?

At the same usage quintile, players whose efficiency ranks 2+ quintiles lower are +12.7 points more likely to drop a usage quintile.

Sample: 10,228 player-seasons, 1,820 players

SupportedIn sample only+12.7 points (+9.4 to +15.8)TS07

Held out, do transition states improve next-season forecasts of usage, efficiency and minutes?

No variant improves usage, efficiency or minutes forecasts on established players; efficiency gets about 1.5% worse under every variant. A forecast from transitions alone is 8-19% worse than the baseline.

Sample: 10,228 player-seasons, 1,820 players

Not supportedHeld outUsage best +0.019; efficiency -0.032; minutes best +0.142 (MSE) (-0.001 to +0.042; -0.043 to -0.022; -0.082 to +0.380)TS11

Held out, do transition states improve next-season creation forecasts?

Not against the current baseline. No creation variant's interval excludes zero in its favour; even the best adds error (-0.3% change), and 1 of 7 make it worse beyond chance. Against baseline Revision 2 one variant cut creation error by 0.9%; the history mean (Revision 3) took that gain.

Sample: 10,228 player-seasons, 1,820 players

Not supportedHeld out-0.052 MSE (creation points squared), -0.3% of baseline error (-0.118 to +0.008)TS10

Do usage, creation and efficiency moves this season predict each other's moves next season beyond each one's own move?

Once a dimension's own last move is known, the other two add little: the lookup's best smoothing strength is 500-1373 player-seasons, and held out the move pattern improves the next-quintile log score by only +0.004 (usage) to +0.002 (creation).

Sample: 10,228 player-seasons, 1,820 players

MixedHeld outLog score gain +0.004 / +0.002 / +0.005 (usage / creation / efficiency) (+0.002 to +0.006; +0.000 to +0.003; +0.003 to +0.007)TS09

Given one dimension leads, how likely are the others to move, and which way?

Pairwise, with the follower flat: usage rise -> efficiency rise next season 23% vs 14%; within two seasons +13.3 points. Most pairs move the follower's odds by under 5 points.

Sample: 10,228 player-seasons, 1,820 players

SupportedIn sample onlyLargest: minutes->usage +8.8, usage->efficiency +8.2 points next season (+6.7 to +11.2; +5.0 to +12.0)TS05

Griffin's example: usage and efficiency rose but creation has not; what next?

After a season in which usage and efficiency rose and creation stayed flat (196 player-seasons), creation rose next season 8% of the time, the same as any player whose creation was flat (8%).

Sample: 10,228 player-seasons, 1,820 players

Not supportedClean null8% vs 8% (8% to 9% (smoothed cell))TS08

Which dimensions of a player's season are stable?

Year to year, creation repeats most (r 0.92), then usage (0.87), offensive impact (0.76), role minutes (0.77) and defensive impact (0.66). Games played barely repeats (0.21).

Sample: About 5,900 player-seasons per dimension, walk-forward

SupportedIn sample onlyYear-to-year r: creation 0.92, usage 0.87, offense 0.76, defense 0.66, games 0.21TB02

What explains a player's next three seasons of value (the factor model)?

Current value 29%, scoring 14%, vision 8%, age/experience/draft 7%, athleticism stand-ins 6.5%, touch 2%, size about 1% (Shapley shares, 12,448 player-seasons 1982-2021, in sample).

Sample: 12,448 player-seasons

SupportedHeld outCurrent value 29%, scoring 14%, vision 8%, age/experience/draft 7%, athleticism stand-ins 6.5%, touch 2%, size about 1% (Shapley shares, 12,448 player-seasons ...E17

Which skills change most from one year to the next?

True one-year change as a share of the league spread: FTA/36 0.51, 3P% 0.50, FGA/36 0.49, turnovers 0.47 … blocks 0.30, offensive rebounds 0.28.

SupportedIn sample onlyIntervals per skill (e.g. 0.50 to 0.52)T01

Do public tracking summaries add to the factor model?

No. Future BPM explained: 66% from what the market knows, 69% with box factors, 69% with tracking added.

Not supportedClean null66% from what the market knows, 69% with box factors, 69% with tracking addedE19

Are outlier skills worth more than a straight line says (the Curry question)?

No: gradient boosting 0.640 vs linear 0.639 out of sample. Every model is about 1 point too cautious on its own top forecasts.

Not supportedClean nullgradient boosting 0.640 vs linear 0.639 out of sampleE20

Does value = efficiency x possessions work as a forecasting structure?

Direct and parts-built value forecasts are equally accurate (R-squared 0.65 vs 0.65). Of the variance in value surprises, the efficiency part carries 62%, the possession part 28%.

Sample: About 5,900 player-seasons per dimension, walk-forward

SupportedHeld outR-squared 0.66 direct vs 0.66 from parts; the composed forecast is now slightly better (MSE(direct) - MSE(composed) 1.1 to 73.7 (was -7.4 to 66.9))TB11

Are some players persistently under- or over-forecast by the baseline?

They do not: lag-1 r +0.001 (-0.030 to 0.027), permutation p 0.47; the stable player share of the misses is 1.0% (null 95th percentile 1.3%). Updated 2026-10-15: was Lag-1 r +0.003; player share 1.1% (null 95th pct 1.3%) (-0.028 to 0.029) before the 2026-10-05/07 re-runs; numbers refreshed from the current output.

Sample: 6,525 rows, 1,288 players

Not supportedClean nullLag-1 r +0.001; player share 1.0% (null 95th pct 1.3%) (-0.030 to 0.027)FM05

When the model misses a player badly, do his 20 look-alikes miss too (type or individual)?

About 47-48% of look-alikes also beat the model, close to the 50% chance rate: type and individual are not separated.

Not supportedClean nullAbout 47-48% of look-alikes also beat the model, close to the 50% chance rateE22

Do players who defy their height bucket (Harden, Giannis, Draymond) beat forecasts?

No. Defiers beat the factor model as often as everyone else; adding the mismatch makes star forecasts slightly worse and value forecasts no better (−0.1 R² points, −0.5 to +0.1, earlier run). 1,073 players defied their bucket in at least one season.

Sample: 1,073 players

Not supportedClean nulladding the mismatch makes star forecasts slightly worse and value forecasts no better (−0.1 R² points, −0.5 to +0.1, earlier run)E23

Does a coach's player-growth record travel with him?

As a lead, yes: +0.36 (+0.11 to +0.60) at his new team. One test of about 19, so it needs confirming on another rating.

SupportedHeld out+0.36 (+0.11 to +0.60)T13

Does any organization grow players faster in a way that lasts?

No: an organization's past player growth does not carry to its next players (slope −0.09, −0.20 to +0.00); young players and shooting show no carry-over either.

Not supportedClean nullan organization's past player growth does not carry to its next players (slope −0.09, −0.20 to +0.00)T12

Do players who join a team whose players are growing improve through skill or setting?

Joiners rise at once: +0.35 (+0.13 to +0.55), which points to the setting rather than learned skill.

SupportedIn sample only+0.35 (+0.13 to +0.55)T14a

Do players who join a team whose players are growing improve through skill or setting?

Leaving such a team costs nothing measurable: -0.20 (-0.42 to +0.06).

Not supportedClean null-0.20 (-0.42 to +0.06)T14b

Where does each Bulls player's level usually go in one and three seasons?

A normal path with an 80% band for every skill of each Bull with a 2025-26 season. On 2010-15, a window the rule was not chosen on, the band covers 81% at three seasons; three-point volume bands run narrow (75%).

SupportedHeld outA normal path with an 80% band for every skill of each Bull with a 2025-26 seasonT23

Does Durant's skill-based game age better than the curve says?

His skill index held after 30 (+1.02 at 28, +1.06 at 37) but his explosiveness proxies fell by more than a league spread. His impact fell 0.36 points a year after 31, close to the 0.39 the age curve predicts. He has not beaten the curve.

Sample: 5 seasons at 31+

Not supportedIn sample onlyDurant impact change after 31: -0.36/yr vs -0.39 predicted (beat by +0.02)TA10

Does LeBron beat every aging trajectory, as Griffin thinks?

LeBron beat the age curve by +0.27 points a year over 10 seasons from 31, and kept his explosiveness proxies near his 27-30 level into his 40s (rim share 44% at 41). Kawhi (+0.85) and Butler (+0.46) beat it by more.

Sample: 10 seasons at 31+

SupportedIn sample onlyLeBron beat the age curve by +0.27 Q per yearTA11

Does the history-mean input (F1) help dimensions beyond usage and creation?

Adding the mean of a player's last three seasons, weighted by how much he played in each, cuts held-out forecast error on 19 of 24 dimensions. Established players: creation 10.0%, usage 1.8%, impact 1.4%, value 1.5%.

Sample: 5,914 established rows (impact, usage, creation); 6,203 (value)

SupportedHeld outMSE reduced, established players (ablation inside the Revision 4 baseline): creation 10.0%, usage 1.8%, impact 1.6%, value 1.5%; 19 of 24 dimensions passed the declared screening rule (8.4 to 11.8% (creation); 1.3 to 2.3% (usage); 1.1 to 2.2% (impact); 0.8 to 2.3% (value); 90% player bootstrap)TB31

Does the baseline over-weight a short last season?

Yes, and fixed: the history mean entered the baseline as Revision 3 and stays in Revision 4. Taking it out of the current baseline raises established-player error by 10.0% (creation) and 1.8% (usage). Returning stars stay under-forecast (Curry 2020-21: 25.8 vs 34.9).

SupportedHeld outAdopted (baseline Revision 3). Inside Revision 4, the history-mean block cuts established-player error: creation 10.0%, usage 1.8%; Curry 2020-21 usage forecast 24.0 (Revision 2) to 25.8 (Revision 4; actual 34.9) (8.4 to 11.8% (creation); 1.3 to 2.3% (usage); 90% player bootstrap, trajectory_baseline.json T4)FM03

Does a state-space model with exposure-weighted observation noise improve on ARMA?

Letting a season's noise grow as its minutes shrink cuts held-out error vs ARMA on every dimension with an exposure: efficiency +3.9%, usage +6.7%, creation +5.8%.

Sample: 5,914 established player-seasons (9,850 all) per rate dimension

SupportedHeld outChange in MSE vs ARMA, established players: efficiency +3.9%; usage +6.7%; creation +5.8%; minutes per game +2.8%; defense +2.0% (efficiency 3.0 to 4.9%; usage 5.5 to 8.1%; creation 4.4 to 7.6%; minutes per game 2.2 to 3.4%; defense 1.4 to 2.6% (90% player bootstrap))SS02

Does an ARMA model per dimension, pulling in all previous seasons on an age-and-stage time axis, beat the baseline walk-forward?

It does not. For established players ARMA(1,1) has higher forecast error than the baseline on efficiency (-7.4%), usage (-13.3%) and minutes (-10.1%) and ties on creation, value and defense.

Sample: 5,914 established player-seasons (9,850 all) per rate dimension

Not supportedHeld outChange in MSE vs baseline (negative = worse): efficiency -8.5%; usage -15.3%; minutes per game -11.1%; games -4.0% (efficiency -10.9 to -6.3%; usage -17.6 to -12.9%; minutes per game -12.6 to -9.4%; games -5.0 to -3.0% (90% player bootstrap))SS01

Does a Kalman-filter model with a latent level drifting by age and stage beat the baseline for established players?

Not against the current baseline (Revision 4, which holds the history mean). It is better only on defense (+1.0%, 0.3 to 1.7%) and worse on the other six dimensions, including creation (-4.9%, -6.9 to -3.0%). Against baseline Revision 2 it was better on creation (+5.6%) and defense (+3.2%).

Sample: 5,914 established player-seasons (9,850 all) per rate dimension

Not supportedHeld outChange in MSE vs baseline: defense +1.0%; creation -4.9%; efficiency -4.2%; usage -7.6%; minutes per game -8.0% (defense 0.3 to 1.7%; creation -6.9 to -3.0%; efficiency -6.1 to -2.6%; usage -9.2 to -6.0%; minutes per game -9.3 to -6.7% (90% player bootstrap))SS03

Where does each model win, by the target season's minutes?

Added after. Error vs the baseline, efficiency: +19.9% when the target season has under 500 minutes, -8.2% at 2,000+.

Sample: 5,914 established player-seasons (9,850 all) per rate dimension

SupportedHeld outefficiency: under 500 minutes +15.2% (13.0 to 17.5%); 2,000+ -10.1% (-13.7 to -7.2%); usage 2,000+ -11.5% (-13.7 to -9.3%); minutes per game 65+ games -20.1% (-21.9 to -18.1%) (in parentheses; 90% player bootstrap)SS08

Does a fixed 50/50 average of models 2 and 4 improve on model 2?

Added after. Not for established players (usage -1.1%); it helps returning stars (usage +27.8%) and defense (+1.3%).

Sample: 5,914 established player-seasons (9,850 all) per rate dimension

MixedHeld outMSE change vs model 2, established: efficiency +0.0%, usage -1.1%, defense +1.3%; returning stars: usage +27.8%, creation +15.0% (est. efficiency -0.7 to 0.8%; est. usage -1.8 to -0.4%; est. defense 0.9 to 1.7%; stars usage 10.5 to 51.6%; stars creation 2.0 to 32.9% (90% player bootstrap))SS09

What state resolution does the data support?

Held out, deciles beat quintiles on log density for every dimension (+0.033 to +0.118); a smooth percentile model ties deciles except a +0.010 gain for defense.

Sample: 10,228 player-seasons, 1,820 players

SupportedHeld outDecile minus quintile: usage +0.096, creation +0.118, efficiency +0.048 (+0.085 to +0.107; +0.106 to +0.131; +0.038 to +0.058)TS12

Does the foul-drawing skill swap move the explosiveness index, its age curves, or the named players?

With shot-mix-adjusted foul drawing in place of FTA/FGA, the reliance index correlates 0.9954 with the old one and 30 of 696 players change tertile. The free-throw trait now peaks at 27 (was 24); the other curves do not change.

Sample: 696 players

SupportedIn sample onlyReliance correlation 0.9954; 30 of 696 change tertile; FT-trait peak 24 to 27; 31-35 change -0.3 to -0.331 spreads (Peak interval 24 to 28; 31-35 -0.4357 to -0.2351 (90%, 200 player bootstraps))FT07

Can a model give calibrated probabilities for each kind of breakout over the next one to three seasons, for every player, better than age and draft slot?

A walk-forward logistic model gives every player the chance of seven breakout types (jump or multi-season climb) and of a first starter-level or star-level season within 1-3 seasons. Pooled over the seven types, its three-season forecasts beat age plus draft slot by 4.2% in Brier score (3.3% to 5.3%); any-breakout AUC 0.76 vs 0.72. The probabilities are calibrated.

Sample: 32,683 type-rows (4,669 player-seasons), 1,253 breakouts

SupportedHeld outBrier skill vs age + draft slot, breakout within three seasons, seven types pooled: 4.2%; vs age alone 5.5%; next-season jumps 3.1% (3.3% to 5.3%; 4.4% to 6.8%; 2.2% to 4.1% (90% player bootstrap, 500))U09

Does a full-history model with age as the time axis forecast better than the three-season history mean?

Answered by SS01: an ARMA model on an age-and-career-stage axis forecasts next season worse than the trajectory baseline for established players (efficiency, usage and minutes), and ties on creation, value and defense. It wins only for returning stars and low-minute seasons (see SS08).

Not supportedHeld outSee SS01: change in squared error vs baseline, efficiency -8.5%, usage -15.3%, minutes -11.1% (negative = worse) (SS01's 90% player bootstrap)U27

Does beating one's regular season in the playoffs signal real improvement?

Yes: each point of playoff lift predicts 0.14 points of next-season improvement (+0.12 to +0.17), beyond his level and age.

Sample: 1924 consecutive player-seasons

SupportedIn sample only0.145 Game Score per 75 per point of lift (+0.118 to +0.172)RI06

Where does the overall-impact age curve peak once survival is modelled separately and leavers count at replacement level?

Yes. Survival times change-if-he-stays, with leavers at replacement level, peaks at 26 (90% 25 to 26) for a player in the league at 21, against 28 for the front-page curve; prime window 24-29 vs 25-30. At 28 the front-page curve is 0.28 league spreads higher (0.22 to 0.33).

Sample: Overall impact Q (front-page measure), pairs 1996-97 to 2025-26

SupportedIn sample onlyExpected-trajectory peak age 26 (front-page curve 28); front-page minus expected at 28: 0.19 spreads (was 0.28) (peak 25 to 26; gap 0.13 to 0.24 (was 0.22 to 0.33; 90%, 200 player bootstraps))SV01

Does modelling who stays in the league separately improve the trajectory baseline's multi-season value forecast?

Yes. Out of sample on 7,501 origins (2001-02 to 2022-23), multiplying the baseline's value forecast by each player's chance of playing cuts its squared error on value over the next three seasons by 4.5% (1,205; 90% 892 to 1506); seasons with no minutes count zero.

Sample: 7,501 origins, 1,417 players, walk-forward

SupportedHeld outMSE baseline minus split: 1,205 (4.5% of the baseline's) (892 to 1506 (90%, 1,000 player bootstraps))SV03

Is the gain from counting leavers, or from splitting the model?

Yes, modestly. The split beats a one-equation model with the same inputs by 419 squared points (90% 227 to 626), 1.6% of that model's error.

Sample: 7,501 origins

SupportedHeld outMSE one-equation minus split: 419 (227 to 626 (90%))SV04

Is an age table enough, or does survival need player-level inputs?

No. Multiplying the baseline by the share of players his age who keep playing changes its squared error by +550 (90% -428 to 1670): not distinguishable from zero, and worse in the point estimate, because exits fall on low-value players and a flat discount shrinks stars.

Sample: 7,501 origins

Not supportedHeld outMSE age table minus baseline: +550 (-428 to 1670 (90%))SV05

Is there selection on the season a player leaves that no model of observables removes?

Yes. Players who dropped out for a season and returned were -0.20 league spreads (90% -0.29 to -0.12) below stayers with the same age, rating, minutes and injuries two seasons later (170 returners). Updated 2026-10-15: was Returners minus stayers, two-season change in Q: -0.23 spreads (-0.31 to -0.13 (90%)) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: Q, 1996-97 to 2025-26

SupportedIn sample onlyReturners minus stayers, two-season change in Q: -0.20 spreads (-0.29 to -0.12 (90%))SV06

Do the trait peaks and the explosive-versus-skill contrast survive season-y weights?

Tested. Explosive peaks did not move (5 of 6 still peak at 21); skill peaks moved later, not earlier (three-point % 26 to 36, mid-range 28 to 32); overall impact moved earlier (28 to 26).

Sample: 200 player bootstraps

Not supportedIn sample onlyOverall-impact peak 28 -> 26; skill group 27-31 -0.07 -> -0.03 spreads (peak 26 to 28; skill -0.11 to +0.06)SV07

Is this season's exposure a safe weight for a delta-method age curve of a rate?

A player's attempts track his luck that season (3P attempts vs 3P%, ages 25-30: r = 0.35), so season-y weights tilt every step down: under them the skill group falls 0.31 spreads from 27 to 31 and Figure 3 reverses.

Sample: 200 player bootstraps

SupportedIn sample onlySkill group change 27-31: season-y weights -0.31 vs equal -0.03 vs last-season -0.07 (-0.35 to -0.27; -0.11 to +0.06; -0.12 to -0.01)TR01

Where does the overall-impact age curve peak with weights known in season y?

Refit peak 26 (26 to 28); 26 and 28 are tied (+0.00). The old curve rose too steeply from 21 (level at 28 +0.66 vs +0.84 spreads).

Sample: 200 player bootstraps

SupportedIn sample onlyPeak 26 (report 28); change from 28 to 33 -0.49 spreads (peak 26 to 28; -0.57 to -0.40)TR02

Does Figure 4's offense curve survive counting players who lose their minutes?

Offense change at 27-28 (age in the later season): -0.19 per 100 (report -0.07); flat at 25-26. Defense unchanged.

Sample: 200 player bootstraps

SupportedIn sample onlyOffense change 27-28: -0.19 per 100 per season (report -0.07) (-0.25 to -0.15)TR03

When do shooting percentages peak with weights known in season y?

Refit peaks: three-point % 36 (32 to 36), mid-range 32 (27 to 33); last-season weights agree on no decline but show a flat, not rising, three-point curve.

Sample: 200 player bootstraps

SupportedIn sample onlyThree-point % change 27-31: +0.24 spreads (equal weights); +0.05 (last-season weights) (-0.10 to +0.63; -0.17 to +0.23)TR04

At each career-minute checkpoint, does a forecast built only from the first N minutes explain more of the career peak (best 3 seasons of SiPM) than draft slot and age, out of sample?

Yes, from the first 100 minutes, also with no look-ahead in SiPM. At 1,143 minutes the as-of forecast explains 0.36 of the spread in career peaks; draft slot and age 0.02. The leaky original's box forecast said 0.42 and 0.10; most of the drop is the stricter yardstick (draft slot drops too).

Sample: 1,416 players; fit 694 (1997-2006 debuts), test 722 (2007-16 debuts)

SupportedHeld outR^2 gain over draft slot and age (as-of): +0.15 at 100 min, +0.34 at 1,143 min (+0.08 to +0.20; +0.23 to +0.42 (90% player bootstrap))PK01

At how many career minutes does a forecast made only from those minutes explain half the variance of the realized career peak?

Not as a constant. As of each checkpoint, the forecast reaches R^2 0.5 at 3,680 minutes (2,414 to 4,701; 24% of resamples never reach it); fitted the other way round, 880 minutes. The leaky original said 2,549 minutes and 445 minutes.

Sample: 1,416 players; fit 694 (1997-2006 debuts), test 722 (2007-16 debuts)

MixedHeld outR^2 0.5 at 3,680 minutes (as-of forecast; R^2 0.36 at 1,143) (2,414 to 4,701; 24% of resamples never reach it; R^2 at 1,143 0.25 to 0.42 (90% player bootstrap))PK02

Does a model with draft slot and early production beat production alone at forecasting the career peak?

No detectable gain from 250 minutes, with no look-ahead in SiPM: adding draft slot and age to the as-of forecast changes R^2 by at most 0.010 from 250 minutes on, in both directions (reverse at most 0.018); every interval includes zero. At 100 minutes it adds +0.019 (+0.000 to +0.044), at the edge of detection; on the measured-impact peak +0.023 (+0.002 to +0.042).

Sample: 1,416 players; fit 694 (1997-2006 debuts), test 722 (2007-16 debuts)

Not supportedClean nullR^2 change from adding draft slot (as-of): +0.019 at 100 min, +0.005 at 500, +0.006 at 1,143 (+0.000 to +0.044; -0.016 to +0.022; -0.014 to +0.024 (90% player bootstrap))PK03

At matched experience, does the full production SiPM (lineup and box parts) forecast the career peak better than the first-N-minutes box forecast?

Among careers of 3,000+ minutes, as-of SiPM after season 1 against the as-of forecast at 1,000 minutes: R^2 difference -0.00; after season 3 against 3,000 minutes +0.18.

Sample: 1,416 players; fit 694 (1997-2006 debuts), test 722 (2007-16 debuts)

Not supportedClean nullS1 minus N1000 -0.00; S2 minus N2500 +0.03; S3 minus N3000 +0.18 (-0.07 to +0.10; -0.02 to +0.10; +0.12 to +0.26 (90% paired player bootstrap))PK04

Does early production reveal the career peak better for some positions?

Suggestive only (group differences not tested): at 500 minutes the as-of forecast explains 0.35 of the spread in bigs' peaks, 0.39 for guards and 0.21 for wings.

Sample: 1,416 players; fit 694 (1997-2006 debuts), test 722 (2007-16 debuts)

MixedHeld outR^2 at 500 min (as-of): bigs 0.35, guards 0.39, wings 0.21 (bigs 0.22 to 0.44; guards 0.25 to 0.50; wings 0.09 to 0.31 (90% bootstrap within group))PK05

Is the early edge over draft slot coming from box production, or only from the coach's minutes allocation?

Production alone (no minutes per game) gains +0.15 R^2 over draft slot at 250 minutes and +0.30 at 1,143, with the peak on a scale no test player shaped.

Sample: 1,416 players; fit 694 (1997-2006 debuts), test 722 (2007-16 debuts)

SupportedHeld outProduction only minus draft and age (as-of peak): +0.15 at 250 min, +0.30 at 1,143 (+0.08 to +0.21; +0.20 to +0.39 (90% player bootstrap))PK06

Does knowing how roster competition moved improve held-out forecasts of next-season rebounding, steals, blocks, fouls, assists and defensive RAPM?

No. Adding the two usage-shift terms to a walk-forward model (age curve, last season, teammates' stat competition) changes held-out error by -0.16% to +0.10%; steals and blocks get slightly worse.

Sample: 5,691 held-out pairs; player bootstrap of errors

Not supportedHeld outheld-out MSE change, fouls -0.09%; steals +0.10% (-0.35 to +0.16; +0.04 to +0.16)RU09

At a career-minute checkpoint, does the full rating computed as of that day forecast the career peak better than box rates from the same minutes?

A little, and only when SiPM is also the yardstick: adding as-of SiPM (lineup part included) to the first-N-minutes box forecast adds +0.03 R^2 at 500 minutes and +0.04 at 1,143 on the SiPM peak, but -0.00 on the measured-impact peak.

Sample: 1,416 players; fit 694, test 722; 10,430 as-of checkpoint ratings on 3,123 days

MixedHeld outR^2 change, (bs) minus (b): +0.03 at 500, +0.04 at 1,143, +0.05 at 3,000 (+0.02 to +0.06; +0.02 to +0.06; +0.02 to +0.09 (90% player bootstrap))PK07

Do young NCBs' own season-to-season changes show slower defensive growth?

No. Their one-season defensive change relative to others at the same age and level is +0.10 per 100 at 22 or under and +0.05 at 23-25: as fast or faster.

Sample: 11,630 pairs at risk, 9,139 observed, 2,091 players

Not supportedIn sample only+0.10 per 100 defensive change, NCB 22 or under vs others (+0.02 to +0.18 (90%))LR25

Does adding LB's terms to the multi-season value forecast reduce held-out error?

No, a tie: adding the five profile indicators to the engine changes three-season VORP error by -0.5% (engine minus profiles +0.018, -0.022 to +0.058 (90%)); the engine stays as it is.

Sample: 5,688 test origins, 1,468 players

Not supportedHeld out+0.018 squared VORP (engine minus engine with profiles, three-season sum, origins 2012-2022) (-0.022 to +0.058 (90%))LR26

Does the overall-impact age curve differ by position?

Guards gain +0.86 (+0.72 to +0.96) spreads of overall impact from 21 to 27, bigs +0.40 (+0.29 to +0.53); guards peak at 28 (26-30), bigs and wings at 26. The curves are 0.73 spreads apart at 31 (0.53 to 0.95). Updated 2026-10-15: was 0.87 (0.66 to 1.09) apart, guards +0.93 and bigs +0.38, before the 2026-10-09 SiPM reruns lowered guards' gain; the gap is still well above the label-shuffle 95th percentile (0.37).

Sample: 12382 pairs; 200 player bootstraps; 100 label shuffles

SupportedIn sample onlyGuard minus big, change since 21 at age 31: 0.73 league spreads (0.53 to 0.95 (90%))TA13

Does ball security age differently by position?

Guards cut their turnover rate through their 20s and peak at 30 (25-30); bigs peak at 25 (21-25) and turn the ball over more from 27 to 31 (-0.44 (-0.63 to -0.24) spreads, up = better). Updated 2026-10-15: interval bounds moved by 0.01 after the 2026-10-09 SiPM reruns.

Sample: 12382 pairs; 200 player bootstraps; 100 label shuffles

SupportedIn sample onlyLargest gap between position curves: 0.99 league spreads at 30 (0.77 to 1.37 (90%))TA14

Do explosive traits fade at the same pace for every position?

From 21 to 27 bigs' blocks change by -0.47 (-0.61 to -0.32) spreads while guards' barely move (-0.00 (-0.05 to +0.05)); dunks peak at 21 for all three, but bigs' dunks change by -0.52 (-0.65 to -0.39) against guards' -0.26 (-0.30 to -0.21). Updated 2026-10-15: small moves (0.01) after the 2026-10-09 SiPM reruns.

Sample: 12382 pairs; 200 player bootstraps; 100 label shuffles

SupportedIn sample onlyBlocks gap 0.82 spreads at 33; dunks gap 0.67 at 33 (blocks 0.62 to 1.05; dunks 0.48 to 0.85 (90%))TA15

Does free-throw shooting develop differently by position?

From 21 to 27 guards gain +0.49 (+0.30 to +0.64) spreads of FT%, wings +0.48 (+0.30 to +0.69), bigs +0.03 (-0.16 to +0.22); bigs peak at 24 (22-28). Updated 2026-10-15: the largest gap was 0.94 (0.63 to 1.28) before the 2026-10-09 SiPM reruns.

Sample: 12382 pairs; 200 player bootstraps; 100 label shuffles

SupportedIn sample onlyLargest gap: 0.91 league spreads at 33 (0.62 to 1.27 (90%))TA16

Does forecast = w(minutes) x draft expectation + (1 - w) x the baseline without draft terms, w fitted walk-forward, beat the production next-season value forecast?

No. Moving draft slot from the baseline's fixed terms into a prior that fades with minutes changed error by -0.5% on all rows and -12.0% under 250 career minutes. Production unchanged.

Sample: 9,850 rows, 1,935 players

Not supportedHeld outSquared error removed vs production: -0.5% all rows; -12.0% under 250 minutes; -3.9% at 250-1,000 (-0.8 to -0.2%; -16.8 to -7.7%; -5.8 to -2.2% (90%, 1,000 player bootstraps))DP01

Does blending the draft-and-age model into the box + as-of SiPM peak forecast with a weight fading in minutes beat that forecast?

A tie: +0.1% (-0.8 to +0.8%). Draft slot refit as a covariate at each minutes checkpoint does at least as well (+1.1%) and helps at 100 minutes (+2.6%, +0.6 to +4.6%).

Sample: 5,293 player-checkpoints, 628 players

Not supportedClean nullError removed vs the peak forecast (bs): R +0.1%; per-checkpoint covariate +1.1% (-0.8 to +0.8%; -0.5 to +2.6% (90%, 1,000 player bootstraps))DP03

Does w = error of the performance forecast / (sum of both errors), by minutes, beat production?

No, worse on all three targets: next-season value -12.3%, three-season value -12.6%, peak -4.5%. The weight ignores that the two forecasts' errors move together, so it leans on the draft prior far too long.

Sample: As DP01-DP03

Not supportedHeld outError removed vs production: next -12.3%; three-season -12.6%; peak -4.5% (-15.9 to -9.2%; -20.4 to -5.6%; -9.0 to -0.8% (90%))DP04

When the breakout model says X%, do about X% happen?

Held out, forecasts match outcomes: breakout within three seasons, mean forecast 3.91% vs 3.83% happened, calibration slope 0.98. Players in their first three seasons: slope 1.01.

Sample: Ten bins of forecast probability, seven types pooled

SupportedHeld outCalibration slope 0.98 (three seasons), 1.03 (next season), 1.00 (arrivals) (0.92 to 1.05; 0.98 to 1.10; 0.96 to 1.08 (90% player bootstrap, 100))BK01

Does a fitted logistic on player history, age, draft, position and roster context forecast breakouts better than the 'players like him' lookup?

On the precedent study's own rows and labels: next-season breakout Brier skill 3.8% (AUC 0.77 vs 0.71); breakout or climber event within three seasons 2.4% (AUC 0.74 vs 0.72).

Sample: 5,351 and 4,596 player-seasons

SupportedHeld outBrier skill vs precedent lookup: 3.8% (next season), 2.4% (three seasons) (2.4% to 5.2%; 0.8% to 3.9% (90% player bootstrap))BK02

How does the chance of each breakout type change with age?

Chance of any breakout within three seasons: 31.4% at 21-23, 17.6% at 25-27, 5.8% at 29-31. Efficiency breakouts fall 44-fold over that span; defensive ones 2.6-fold.

Sample: 8,880 player-seasons

SupportedIn sample only21-23 over 29-31: any 5.4x, efficiency 44x, usage 15x, creation 5.4x, defense 2.6x (any 4.3 to 6.7; defense 1.7 to 4.2; creation 3.4 to 9.1 (90% player bootstrap))BK03

Do breakout odds differ by position for young players?

At 21-25, any breakout within three seasons: guards 32.6%, wings 25.4%, bigs 22.4%. Creation: guards 12.8% vs bigs 2.2%.

Sample: 3,323 player-seasons

SupportedIn sample onlyGuard minus big, ages 21-25: any +10.2 pts, creation +10.7, defense +3.5 (+4.6 to +15.9; +7.4 to +14.1; +0.6 to +6.5 (90% player bootstrap))BK04

Does position change a young player's chance of reaching star level?

Not supported: a first top-15 value season within three seasons, ages 21-25, guards 6.8%, wings 4.0%, bigs 5.6%; the guard-big difference is not distinguishable from zero.

Sample: 3,182 player-seasons

Not supportedClean nullGuard minus big +1.1 pts (star), +0.1 (starter) (-1.8 to +4.5; -5.3 to +5.8 (90% player bootstrap))BK05

Do role openings known before the season improve breakout forecasts, beyond the player's own history?

Removing the team-context inputs (team change, vacated minutes and plays, opening and unclaimed share, heir, star gone) makes next-season usage-jump forecasts 2.0% worse and creation-jump forecasts 2.4% worse, held out. Other types are untouched; the help fades over three seasons.

Sample: 5,439 player-seasons per type

SupportedHeld outBrier worsening without context: usage 2.0%, creation 2.4%, seven types pooled 0.89% (0.6 to 3.6; 0.8 to 4.1; 0.36 to 1.46 (90% player bootstrap))BK06

Can the model foresee a player's first starter-level or star-level season?

First top-15 value season within three seasons: AUC 0.94 vs 0.77 for age plus draft slot; Brier skill 20.1%. Starter level (top 60): AUC 0.83.

Sample: 4,162 player-seasons, 123 star arrivals

SupportedHeld outBrier skill vs age + draft: star 20.1%, starter 16.4% (13.2% to 26.4%; 12.9% to 20.3% (90% player bootstrap))BK08

Did the age curve of breakouts change between eras?

Mixed: for players 25 and under the chance of any breakout within three seasons fell (-9.6 pts at 22 and under), with defense and value down and usage and creation up. From 26 on, no change is distinguishable from zero.

Sample: 8,880 player-seasons

MixedIn sample onlyLater minus earlier, age 22 and under: any -9.6 pts, usage +5.3, creation +6.0, defense -4.5, value -6.1 (any -16.3 to -2.8; usage +1.1 to +9.1; creation +1.7 to +10.1 (90% player bootstrap))BK09

Which traits does a team buy at their peak when it adds a 19-21-year-old?

5 of 6 explosive traits (rim-shot share, dunks, transition shots, blocks, offensive rebounds) peak at 19 or 20; dunks per 36 fall -0.29 from 19 to 27.

Sample: 13,987 season pairs; 74-162 pairs at age 19; 200 player resamples

SupportedIn sample onlyDunks per 36, change 19 to 27: -0.40 league spreads (-0.51 to -0.30 (90%, player resamples))WB01

How does a young player's shot diet change with age?

Rim attempts per 36 peak at 23 and fall -0.41 from 21 to 27; corner-three attempts per 36 change +0.02 from 19 to 27.

Sample: 13,987 season pairs; 74-162 pairs at age 19; 200 player resamples

SupportedIn sample onlyRim attempts per 36, 21 to 27: -0.41 (-0.53 to -0.28)WB03

How much of the 25-27-year-old is visible at 19-21?

Own value at 19-21 explains 0.71 of dunks, 0.76 of blocks, 0.69 of assists at 25-27 (out of sample). Updated 2026-10-15: was Blocks per 36 at 25-27, R^2 from own value at 19-21: 0.76 (0.66 to 0.82) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: Walk-forward; outcome at ages 25-27; 1,000 player resamples

SupportedHeld outBlocks per 36 at 25-27, R^2 from own value at 19-21: 0.76 (0.66 to 0.83)WB04

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Best 3-year run centred inside the league-wide prime window (24-29))

Best 3-year run centred inside the league-wide prime window (24-29): 17 of 20 in the top 20 vs 58 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only17 of 20 (top 20) vs 58 of 80 (ranks 21-100)AG05

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Built the peak as a staircase (largest one-season rise under half of the climb))

Built the peak as a staircase (largest one-season rise under half of the climb): 6 of 20 in the top 20 vs 14 of 78 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

Not supportedIn sample only6 of 20 (top 20) vs 14 of 78 (ranks 21-100)AG06

Shot-making and scoring efficiency 28

Do analytics-forward teams push each shot type until the marginal values equalize?

Three minus two with fouls, 2025-26: -0.093 (-0.102 to -0.083) points per attempt (replicated). In the half court, counting offensive rebounds and the opponent's next trip, the gap is +0.009 (-0.006 to +0.024). Non-rim twos still trail threes by +0.129 (+0.118 to +0.139). Updated 2026-10-15: was Three-minus-two value with fouls, 2025-26: -0.093 points per attempt; half court with full accounting +0.009 (-0.102 to -0.083; half court -0.006 to +0.024 (90%, games resampled)) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: All regular-season shots

SupportedIn sample onlyThree-minus-two value with fouls, 2025-26: -0.093 points per attempt; half court with full accounting +0.009 (-0.102 to -0.083; half court -0.006 to +0.024 (90%, games resampled))UE06

Once transition, putbacks and rebounds are accounted for, do half-court threes and twos differ in value?

Half court, no putbacks, heaves or garbage time, net of the opponent's next possession: 2025-26 +0.009 (-0.006 to +0.024); 2021-25 +0.008 (+0.001 to +0.015).

Sample: 2025-26: 96,892 twos, 64,942 threes

SupportedIn sample onlyThree minus two, half court, full possession accounting, 2025-26: +0.009 (-0.006 to +0.024)TW01

Are the twos a team could take instead of threes worth more or less than threes?

2025-26, with fouls: three minus short two +0.100 (+0.089 to +0.111), minus long two +0.222 (+0.208 to +0.237); three just outside the arc minus long two just inside +0.347 (+0.317 to +0.377). Updated 2026-10-15: was Three minus non-rim two, with fouls, 2025-26: +0.129 (+0.118 to +0.140) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: All regular-season shots

SupportedIn sample onlyThree minus non-rim two, with fouls, 2025-26: +0.129 (+0.118 to +0.139)TW02

Does the three-versus-two comparison depend on who shoots the three?

2021-25, threes by prior-season 3P% minus the average two: 38%+ -0.010 (-0.017 to -0.003); below 33% -0.111 (-0.120 to -0.099); no prior record -0.146 (-0.154 to -0.138). Updated 2026-10-15: was Below-33% shooters' threes minus the average two, 2021-25: -0.111 (-0.121 to -0.100) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: Share of threes: 38%+ 32%, below 33% 12%, no prior 22%

SupportedIn sample onlyBelow-33% shooters' threes minus the average two, 2021-25: -0.111 (-0.120 to -0.099)TW03

Has the spread of values across shot zones shrunk as teams optimized?

They have not: rim attempts got more valuable (1.21 to 1.34 points per attempt) and long twos stay far below threes. The weighted spread of zone values barely shrank (0.204 then, 0.183 now; flat since 2008).

Sample: All regular-season shots

Not supportedIn sample onlyZone-value spread change per decade, 2016-25: -0.001 (-0.007 to +0.006)UE07

Is there a visible diminishing return on threes across teams?

They do the opposite: within each season, a higher three-point rate goes with higher three-point value, before and after adjusting for shot type. So the data cannot show the margin; teams that shoot more threes have better shooters.

Sample: 863 team-seasons

Not supportedIn sample only3P points per attempt per +10 points of 3PA rate, 2016-25: +0.016 (+0.006 to +0.025)UE08

Which traits stay stable when a player's role changes?

Among 1,286 role changers, FT%, 3P%, blocks and rebounding keep noise-corrected year-to-year r of 0.83-0.96, barely below same-role players. Fouls, turnover %, 2P%, assist %, steals and shot mix repeat less well, because they depend on the role.

Sample: 1,286 role changers, 3,764 same-role

SupportedIn sample onlyNoise-corrected r, changers vs same-role: FT% 0.92 vs 0.93; fouls 0.87 vs 0.96 (FT% change -0.032 to +0.016)TB12

Does shooting rise when a player's role grows?

Role changers' FT% (+1.79, 1.41 to 2.17), 3P% and pull-up eFG rise against same-role players. FT% barely depends on role, so its rise suggests players given more role were already improving: selection. The test cannot tell selection from flow.

Sample: 1,286 vs 3,764 pairs

MixedIn sample onlyFT% level shift for role changers: +1.79 points (1.41 to 2.17)TB13

Does shooting rise with role, for flow or hot-hand reasons, compared with a bench player who gets two shots and is pulled?

Not supported: when an absence hands players a bigger role, bench players' shot-making falls 0.52 per 100 shots per 10 points of dose (-0.83 to -0.21) and starters' 0.14. Players believe in flow anyway; the narrower warm-up effect is real (UE10).

Sample: 5,934,240 shots

Not supportedIn sample onlyBench shot-making per 10 points of dose: -0.52 per 100 shots (-0.83 to -0.21)UE09

How reliable are Hawk-Eye shot-quality stats over one season?

Shot difficulty 0.98; FG% above expected 0.71 (0.57 on self-created shots); FT% 0.85 (odd vs even games). From regular season to playoffs, FG% above expected repeats at only 0.14 (54 players).

Sample: 54 players

SupportedIn sample onlyShot difficulty 0.98E30

Does half a season of Hawk-Eye shot-making beat raw efficiency at predicting the next half?

Slightly, on Hawk-Eye's own scale (+0.02 to +0.12), not on raw points. Last season's history is as good or better.

MixedHeld outSlightly, on Hawk-Eye's own scale (+0.02 to +0.12)E32

Is the hot hand real?

Small: raw, players shoot 1.1 points worse after a make because they take harder shots; adjusted for the shot (label-safe model), -0.01 after one make and +0.41 after three (+0.29 to +0.53).

Sample: , players

SupportedIn sample onlyadjusted for the shot, -0.01 after one make and +0.41 after three (percentage points) (+0.29 to +0.53 (after three); -0.07 to +0.05 (after one))G04

Does pricing defender distance change the shot-adjusted hot-hand estimate?

In the 2015-16 SportVU games, adding the closest defender's distance at release raises the shot-adjusted hot-hand estimate by 0.14 points (0.07 to 0.21), from -0.05 to +0.09; small next to the estimate's own uncertainty.

Sample: 106,426 shots

SupportedIn sample only+0.137 percentage points (defender-adjusted minus base, k = 1) (0.066 to 0.215)G04b

How much of free-throw rate is shot mix rather than foul-drawing skill?

Yes. Most free throws come from fouled missed twos, and paint and rim attempts draw shooting fouls far more often than jumpers. A foul-drawing measure that holds shot mix fixed is nearly as stable as raw FT rate and reorders players: raw FT rate flatters ball-handling guards with bonus FTs and rim-heavy bigs.

Sample: 3,759 pairs

SupportedIn sample onlyMix-adjusted skill year-to-year r 0.81 (raw FT rate 0.85) (0.79 to 0.83)FT01

Where do free throws come from, by foul type and shot type?

Fouled missed twos give 63% of free-throw attempts, bonus fouls 18% (23% in 1996-2015), and-ones 10%, fouled threes 5%. Shooting fouls per attempt: paint 0.19, rim 0.16, mid-range 0.07, threes 0.01.

Sample: No sampling interval (league totals)

SupportedIn sample onlyFTA share: fouled missed 2 63%, bonus 18%, and-one 10%, fouled missed 3 5%; shooting fouls per attempt rim 0.16, paint 0.19, mid 0.07, three 0.01FT03

Can foul-drawing skill be separated from shot mix?

Shooting fouls drawn against what a player's shot mix implies is nearly as stable year to year as raw FT rate (r 0.81 vs 0.85) and robust to the allocation and location choices (correlations 0.999 and 0.958 with alternatives).

Sample: 3,759 pairs

SupportedIn sample onlyYear-to-year r 0.81 (raw FT rate 0.85); rank correlation with a contest-adjusted version 0.985 (0.79 to 0.83)FT04

Among guards, does height go with defense, and does poor shooting cost value?

A measurable cost of poor shooting shows only among guards who shoot often (about 0.54 BPM); not across all guards.

SupportedIn sample onlyA measurable cost of poor shooting shows only among guards who shoot often (about 0.54 BPM)E24b

When did this tactic change in our data, and does that match the told date (2012-13 on (Rockets, Warriors); the told acceleration is 2014-15 to 2018-19)?

Three-point share of FGA crossed halfway from its 1980s level to today's in 2012-13; largest single shift before 2014-15.

Sample: Team box scores

SupportedIn sample only0.038 in 1985-86 to 0.415 in 2025-26; halfway 2012-13; exploratory break before 2014-15 (permutation p 0.001) (last season +0.402 to +0.428 (90%))ET01

When did this tactic change in our data, and does that match the told date (2012-13 on, with pace and space)?

Long-two share fell from about 30% to 7%; corner threes rose steadily from 1997-98.

Sample: Team zone tables

SupportedIn sample only0.277 in 1997-98 to 0.075 in 2025-26; low point 2025-26; exploratory break before 2016-17 (permutation p 0.001) (last season +0.068 to +0.081 (90%))ET02

When did this tactic change in our data, and does that match the told date (2016-17 on (told: Brook Lopez 2016-17, then league-wide))?

Share of big-man minutes (83 in+) from players taking 3+ threes per 36 roughly doubled in 2016-17 and 2017-18 (series added after the first run).

Sample: Player-seasons

SupportedIn sample only0.000 in 1985-86 to 0.520 in 2025-26; halfway 2016-17; exploratory break before 2016-17 (permutation p 0.001) (last season +0.400 to +0.640 (90%))ET03

Does a career-to-date shooting estimate beat both kinds of prior?

For veterans, yes: FT% +16.7% and 3P% +6.2% better than both kinds of prior.

SupportedHeld outFT% +16.7% and 3P% +6.2% better than both kinds of priorE14a

Does a career-to-date shooting estimate beat both kinds of prior?

Not for rookies' three-point percentage, where there is no career yet to lean on.

Not supportedClean nullNot for rookies' three-point percentage, where there is no career yet to lean onE14b

Does shrinking a shooter toward players like him (size, height, volume) beat shrinking toward the league?

Within a season, yes: 3P% error -8.6% (7.5 to 9.9), FT% -3.7% (3.0 to 4.3), walk-forward over 39 seasons.

Sample: 39 seasons

SupportedHeld out3P% error -8.6% (7.5 to 9.9)E13a

Does shrinking a shooter toward players like him (size, height, volume) beat shrinking toward the league?

No better for next season's 3P%: +1.8% (-0.2 to +3.9). Not adopted. Updated 2026-10-15: was +1.7% (-0.3 to +3.7) before the 2026-10-01 rebuild; numbers refreshed from the current output.

Sample: 39 seasons

Not supportedClean null+1.8% (-0.2 to +3.9)E13b

Does playoff-minus-regular-season true shooting repeat across a player's postseasons?

No: true-shooting lift next-postseason r -0.025 (-0.065 to +0.015); a trait above 1.1 TS points is ruled out (regular-season spread 4.5).

Sample: 3782 player-postseasons, 1061 players; 1924 consecutive pairs

Not supportedClean nullnext-postseason r -0.025; trait SD upper bound 1.10 TS points (r -0.065 to +0.015; trait SD 0.00 to 1.10)RI02

How much does a 19-year-old's shooting improve, zone by zone?

Within players, from 19 to 27: rim +4.4 pp, short two +8.3 pp, long two +8.4 pp, corner three +6.3 pp, above-the-break three +5.8 pp, free throws +6.1 pp (vs league).

Sample: 13,987 season pairs; 74-162 pairs at age 19; 200 player resamples

SupportedIn sample onlyAbove-the-break three FG%, 19 to 27: +5.8 pp (+3.7 to +7.7 (90%, player resamples))WB02

Does early three-point accuracy tell you the later shooter?

Own 3P% at 19-21 (shrunk) explains 0.03 of 3P% at 25-27; every young trait together 0.22.

Sample: Walk-forward; outcome at ages 25-27; 1,000 player resamples

Not supportedHeld outR^2 of 3P% at 25-27 from own 3P% at 19-21: 0.03 (0.01 to 0.05)WB05

Does the threes-versus-twos ordering change with the shooter's age?

2021-22 to 2025-26, field-goal points per attempt: shooters 21 or younger rim 1.26, above-break three 1.00, long two 0.77; three minus non-rim two +0.24 at 21 or younger and +0.22 at 31+.

Sample: Regular-season shots, heaves dropped

SupportedIn sample onlyThree minus non-rim two, shooters 21 or younger: +0.24 points per attempt (+0.22 to +0.26 (90%, player resamples))WB10

Creation and on-ball load 52

When a player's usage rises because a teammate is out, how much does his efficiency change?

When a teammate's absence hands a player one more point of usage, his true shooting falls 0.52 points (0.42 to 0.61). The result holds for injury-only absences, in every era, and in a plain with/without split.

Sample: 561,831 player-games, 10,401 player-team-seasons, 892 team-seasons; intervals resample team-seasons

SupportedIn sample onlyTS -0.52 per usage point; points per 100 plays -0.81 (-0.61 to -0.42 (TS))UE01

Does usage moved by season-level roster changes cost the same as usage moved by a teammate's absence (UE01)?

Yes. Instrumenting a player's season usage with roster competition, team openings, absences and coach changes gives 0.59 TS points per usage point on the 2022-23 to 2025-26 core; the game-level absence method on the same seasons gives 0.54.

Sample: 1,533 player-team-seasons, 564 players; 90% intervals from a player-cluster bootstrap (400)

SupportedHeld out0.59 TS points per usage point (season level); game level 0.54 (0.36 to 0.77; 0.35 to 0.74)UC01

Which part of a player's usage change carries the efficiency cost in next-season forecasts?

Yes, held out. In next-season TS forecasts, the usage change explained by roster, opening, absences, coach and the player's shot habit costs about 0.35 per usage point; the unexplained rest costs -0.01. Separating them cuts error 2.7% against one cost on the whole change; splitting asked from chosen adds nothing (-0.05%). Applying UE01's 0.52 to every usage change makes forecasts 18% worse. (Numbers above are from the 2019-20-onward run. Re-run on 2022-23 to 2025-26: MSE gain, explained/unexplained split vs one cost: 3.5%; fixed 0.52 on all change: -36%.)

Sample: 237 test rows, 237 players; paired player bootstrap (500)

SupportedHeld outMSE gain, explained/unexplained split vs one cost: 3.5%; fixed 0.52 on all change: -36% (0.0 to 6.6%; -53 to -20%)UC05

Does the efficiency cost of more usage depend on what kind of player he is?

Per usage point gained, spacers lose 1.26 TS points and on-ball creators 0.16; the declared contrast is -1.10 (-1.54 to -0.71). High free-throw shooters and self-creators lose less.

Sample: 561,831 player-games, 10,401 player-team-seasons, 892 team-seasons; intervals resample team-seasons

SupportedIn sample onlySpacer minus creator: -1.10 TS per usage point (-1.54 to -0.71)UE02

When usage rises, does a player get worse, or is he handed worse shots?

About 69% of the drop in points per shot is a worse shot diet and the rest is making fewer of the same shots (label-safe shot model; 64% with the published model). Tracking data (2020-26) confirm the shots get more contested.

Sample: 5.9M priced shots

SupportedIn sample onlyPer 10 points of missing usage: shot value -0.38, shot-making -0.17 per 100 shots (label-safe model) (-0.41 to -0.34 (value); -0.25 to -0.09 (making); diet share 0.69 (0.60 to 0.80))UE04

Why do the obvious usage-efficiency comparisons show little cost?

Across players the slope is flat (-0.005 TS per usage point, -0.037 to +0.031) and within a player from season to season it is small (-0.067). Coaches give the ball to players who can carry it, which hides the cost the absence experiment shows.

Sample: 7,146 player-seasons

SupportedIn sample onlyCross-player slope -0.005 TS per usage point (-0.037 to +0.031)UE13

Is the efficiency cost from taking more shots, or from losing the teammate who created them?

Hold fixed how much passing left the floor, and the cost of the extra shots alone shrinks to -0.06 TS per usage point (-0.21 to +0.08), not distinguishable from zero. Players lose efficiency when the guy who set them up is gone.

Sample: 561,831 player-games, 10,401 player-team-seasons, 892 team-seasons; intervals resample team-seasons

SupportedIn sample onlyCost of extra shots with passing held fixed: -0.06 TS per usage point; lost passing -0.18 TS per 10 points of missing assist share (-0.21 to +0.08 (shots); -0.25 to -0.10 (passing))UE03

When a high-usage player sits, does each teammate gain in proportion to his current share?

No: the split is about halfway between equal and proportional. A teammate's share of what the star leaves rises with his current share at 0.45 of the proportional slope. Held out, the strict proportional rule explains 3% of who gains what; a fitted usage-only model 10%.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedHeld outslope of absorption fraction on proportional share 0.46 (1 = proportional, 0 = equal) (0.41 to 0.51 (90%, team-season bootstrap))UA01

Does a teammate's creation skill predict how much of a sitting star's usage he takes?

Yes. Unassisted scorers absorb more of the star's share; dropping creation traits raises held-out error 2.8%. Per SD of the creation composite, a teammate gains 1.2 more points of the star's share, mostly through on-court usage rate.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

SupportedHeld out+1.27 points of the star's share per SD of creation; unassisted share +1.0 per SD (0.92 to 1.62 (creation); 0.56 to 1.46 (unassisted); held-out drop 1.9 to 3.7%)UA03

When the lead creator sits, who takes over his shots?

Last season's creation score (θ) predicts who absorbs the usage (+0.27 usage per 36 per SD, 0.17 to 0.36) beyond prior usage, but not who keeps his efficiency; prior usage alone flags step-ups better (68% vs 62%). 2,213 teammate cases, 289 team-seasons.

Sample: 289 team-seasons

MixedHeld outLast season's creation score (θ) predicts who absorbs the usage (+0.27 usage per 36 per SD, 0.17 to 0.36)T05

Does tracking-data creation predict absorption beyond box-score creation?

Small. Last season's drives and pull-ups per 36 cut held-out error 1.3% (0.2 to 2.4%) once box-score creation traits are in (after the 2026-10-07 game-order fix; before: -0.8%, interval including zero). Status changed 2026-10-15: the held-out error change (-1.3%, 90% -2.4 to -0.2%) excludes zero, so tracked creation does add to the forecast; the gain is small. The 2026-10-07 entry had left this call open. Updated 2026-10-15: was held-out error change -1.2% (leave-one-season-out, 2013-14 on) (-2.4 to -0.2%) before the 2026-10-05/07 re-runs; numbers refreshed from the current output.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

SupportedHeld outheld-out error change -1.3% (leave-one-season-out, 2013-14 on) (-2.4 to -0.2%)UA08

How do players become their team's lead creator?

Of 203 seasons where a player became his team's top creator, 45 were creation breakouts, 27 had a usage breakout that season or the one before, and 61 followed a move to a new team. Most inherited the role at a modest level after a teammate left.

Sample: 203 seasons

SupportedIn sample only45 of 203 new lead creators were creation breakoutsTB18

Does the stayer who becomes the top remaining creator grab more of the opening?

Yes. 'Heirs' (highest prior creation share on the opening roster, not the old top option) gain 2.4 points of team created baskets on average, vs 0.1 for other stayers; 33% gain 5+ points.

Sample: 862 team-season transitions, 8,161 arrivals, 6,163 stayer rows

SupportedIn sample onlyM2 opening x heir +0.107 (0.007 to 0.188 (90%, team-season bootstrap))UD07

Do certain players consistently create 'lucky' teammate shooting, or is it luck?

Teammates' three-point luck carries over for players who change teams (r 0.040, 0.006 to 0.075), beating shuffle and noise nulls. A typical player's true effect is about 0.47 pp on each teammate three (0.18 to 0.65), about 0.41 points per 100 possessions. The free-throw placebo shows nothing.

Sample: 2,458 season pairs; 1,195 players in the multi-season estimate

SupportedHeld outTeam-changer season-to-season r 0.040; true effect SD 0.47 pp per teammate three (0.006 to 0.075 (r); 0.18 to 0.65 (pp))GR01

On which shot types does the teammate effect show?

For team changers, above-the-break persistence is r 0.056 (0.020 to 0.093) and corner threes 0.000 (-0.038 to 0.037). Corner threes are almost all catch-and-shoot, so this is not a clean catch-and-shoot gravity result.

Sample: 2,458 season pairs

SupportedHeld outAbove-the-break r 0.056; corner r 0.000 (0.020 to 0.093; -0.038 to 0.037)GR03

Do teammates shoot better with the lead creator on the floor (the Curry lift)?

Teammates shoot +1.2 TS points better in games he plays. Per-player estimates are mostly noise, and the effect of who replaces him is not separated.

SupportedIn sample onlyTeammates shoot +1.2 TS points better in games he playsE28

How much of one season's teammate shooting lift is signal?

One season of the teammate-shooting measure is about 98% sampling noise; the multi-season estimate's uncertainty (about +/-0.34 pp) is larger than most gaps between players.

Sample: 200 simulated seasons at expected rates

SupportedIn sample onlyShare of one season that is noise: about 98%GR02

Does the gravity estimate split credit correctly between teammates who share the floor?

Supported, but small. Fitting all players on the floor at once moves about 18% of the top players' raw teammate lift to their teammates (+0.24 pp, +0.20 to +0.28) and predicts next season better, yet the list barely reorders (rank correlation 0.985). Murray stays above Jokic (0.72 vs 0.60 pp); the gap's interval (-0.28 to +0.47) cannot say which of them carries it.

Sample: 1.6M threes; held-out targets 2002-03 to 2025-26

SupportedHeld outJOD minus marginal, held out: +0.0038 % of squared error; top-30 teammate part +0.24 pp (+0.0018 to +0.0059 (held out); +0.20 to +0.28 (teammate part))GR07

Is a non-scorer's teammate shooting lift explained by screens and passing rather than gravity?

Mixed. Across 518 players (2016-26), joint gravity tracks potential assists (+0.077 pp per SD, +0.059 to +0.095, height fixed), not scoring volume. Screen assists link to it only through height (+0.018, -0.009 to +0.043). Draymond: joint +0.47 pp, rank 7 of 518; his passing and screening profile predicts +0.26.

Sample: 518 players; 1,000 player resamples

MixedIn sample onlyPotential assists +0.077 pp per SD; screen assists +0.018 (height fixed) (+0.059 to +0.095; -0.009 to +0.043)GR08

Does the efficiency cost of usage depend on whether the team asked for it?

Not shown. On the 2022-23 to 2025-26 core (pull-up labels reliable), usage the roster hands a player costs 0.59 TS points per usage point and usage he takes himself costs 0.30. The gap, 0.29 (-0.14 to 0.65), includes zero; the direction does not hold in both halves, and the held-out prediction no longer beats predicting no change.

Sample: 1,533 player-team-seasons, 564 players; 90% intervals from a player-cluster bootstrap (400)

Not supportedHeld outasked 0.59 vs chosen 0.30 TS points lost per usage point; gap 0.29 (asked 0.36 to 0.77; chosen 0.01 to 0.64; gap -0.14 to 0.65)U02

Is discretionary (self-chosen) shot volume a stable player trait?

Yes. Early-clock pull-ups, step-backs and fadeaways above his team's norm correlate 0.92 between halves of a season and 0.87 year to year. (Numbers above are from the 2019-20-onward run. Re-run on 2022-23 to 2025-26: year-to-year r 0.89; split-half r 0.93.)

Sample: 1,533 player-team-seasons, 843 consecutive-season pairs; player bootstrap (400)

SupportedHeld outyear-to-year r 0.89; split-half r 0.93 (0.87 to 0.91; 0.91 to 0.94)UC02

Is on-court yield (design 3) stable enough to measure a player's choice?

No. A player's share of shots with a better teammate on versus off correlates 0.36 within a season but only 0.16 year to year; it mostly reflects the teammates and the minutes structure. (Numbers above are from the 2019-20-onward run. Re-run on 2022-23 to 2025-26: year-to-year r 0.14; split-half r 0.34.)

Sample: 1,209 player-team-seasons, 636 consecutive-season pairs; player bootstrap (400)

Not supportedHeld outyear-to-year r 0.14; split-half r 0.34 (0.06 to 0.22; 0.28 to 0.39)UC03

Does chosen usage travel with a player beyond what his old usage already says?

No. For 533 team changes, adding the old-team chosen-shot excess and yield to old usage and the new roster changes held-out error by -0.9% (-2.0 to +0.4); old usage already carries the habit. (Numbers above are from the 2019-20-onward run. Re-run on 2022-23 to 2025-26: held-out MSE gain -1.2%; chosen-excess coefficient +0.17 usage points per point.)

Sample: 268 moves; fit into 2022-23 to 2023-24, test into 2024-25 to 2025-26; player bootstrap

Not supportedHeld outheld-out MSE gain -1.2%; chosen-excess coefficient +0.17 usage points per point (-3.5 to +1.0%; -0.21 to +0.66)UC04

Priced against the team alternative, do a player's excess self-chosen plays cost points?

Not on average. Excess discretionary plays are small (about 0.39 per 100 team plays) and score about what teammates would: -0.01 points a season (-0.25 to +0.25) on non-rebuilding teams. Rebuilding teams (own category): +0.34 (-0.01 to +0.71). (Numbers above are from the 2019-20-onward run. Re-run on 2022-23 to 2025-26: excess value -0.24 points per season (non-rebuilding); +0.33 (rebuilding).)

Sample: 779 non-rebuilding and 199 rebuilding rows; player bootstrap

Not supportedIn sample onlyexcess value -0.24 points per season (non-rebuilding); +0.33 (rebuilding) (-0.52 to +0.00; -0.18 to +0.80)UC06

When a star sits, is the team's next-highest-usage player the one who absorbs most?

No in total share. He is the biggest gainer in 19% of held-out absences (chance 8%) and gains less than his share predicts. His on-court usage rate does rise.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedHeld outnext-man-up flag -0.9 points of the star's share; on-court usage rate +0.14 points for a typical star (-1.4 to -0.5; usage-rate 0.01 to 0.26)UA09

Is Griffin's case (usage grows while efficiency drops only a little) common?

Of 227 role breakouts (usage or minutes), 197 (87%) kept impact within 1 point per 100 of the player's past or raised it. Usage and efficiency surprises move together (r 0.24), so roles grow mostly when a player is playing well.

Sample: 227 role breakouts

SupportedIn sample only197 of 227 role breakouts held efficiency (87%)TB06

Do traits (creation, position, shooting, pedigree, age) predict who absorbs a sitting star's usage?

Yes, modestly. Held out, the full trait model cuts error 3.4% against a usage-plus-minutes model and 9.5% against the proportional rule (after the 2026-10-07 game-order fix; before: 4.7% and 12.1%).

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

SupportedHeld outheld-out error -3.3% vs usage+minutes model; -9.5% vs proportional (-5.4 to -1.3%; -12.6 to -6.5%)UA02

Does position overlap with the absent star predict who absorbs his share?

Yes, mostly through minutes: the player at the star's position gets his minutes. Height overlap adds 2.1 points of the star's share per SD; dropping overlap raises held-out error 2.3%.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

SupportedHeld outheight overlap +2.1, ball-handling overlap +0.6 points of the star's share per SD (1.8 to 2.4; 0.3 to 0.8; held-out drop -0.5 to 3.2% (now includes zero))UA04

Do a teammate's shooting skills by shot type predict how much usage he absorbs?

Partly: only shot type matters. Rim finishers absorb less (-1.1 points of the star's share per SD of rim share); shot-making, 3P% and FT% do not predict absorption.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

MixedHeld outrim share -1.2 per SD; shot-making -0.3; 3P% -0.1 (-1.5 to -0.7; -0.7 to 0.1; -0.6 to 0.3; held-out group drop -0.1 to 1.7%)UA05

Do higher picks get more of a sitting star's usage than their traits imply?

No. Dropping draft slot changes held-out error 0.05%; its coefficient is indistinguishable from zero.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedClean nulllog pick -0.0 points of the star's share per SD (-0.4 to 0.4; held-out drop -0.0 to 0.2%)UA06

Do younger (or older) players absorb more of a sitting star's usage?

No. Dropping age and career season changes held-out error 0.01%.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedClean nullage 0.2 points of the star's share per SD (-0.05 to 0.55; held-out drop -0.4 to 0.2%)UA07

Do some coaches concentrate a missing star's usage in one player while others spread it?

Not detectable. Between-coach variance in how concentrated the split is does not exceed a shuffled-coach null (p 0.10, 56 coaches with 3+ events).

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedClean nullbetween-coach statistic 0.099 vs null mean 0.092 (null 95th percentile 0.126; permutation p 0.28)UA10

On Hawk-Eye's shot-quality outcome, which predicts next season's self-created shot-making: touch or history?

History: rank correlation 0.51 vs 0.31 for touch (206 players, 2024-25 → 2025-26). For players with thin histories the edge is borderline.

Sample: 206 players

Not supportedHeld outrank correlation 0.51 vs 0.31 for touch (206 players, 2024-25 → 2025-26)T07

After a role jump, does shooting touch predict pull-up shot-making as well as creation history does (hidden creators)?

Touch matches history, and it is available when history is not. On 64 wing role-player jumps, touch minus shrunk history is +0.075 to +0.521, but 0 of 18 contrasts survive a multiple-test correction; walk-forward, touch adds +0.34 (0.12 to 0.54).

MixedHeld outwalk-forward, touch adds +0.34 (0.12 to 0.54)T06

Do screen-setters add value beyond their rating?

Screen assists are among the most stable numbers in basketball (season to season 0.94), but players who set more do slightly worse next season than their rating says (−0.06 per SD); neither shot-quality measure links them to better shots.

Not supportedClean nullScreen assists are among the most stable numbers in basketball (season to season 0.94), but players who set more do slightly worse next season than their ...E37

Does creation skill protect a teammate's efficiency when he absorbs a sitting star's usage?

Not shown in this design. Teammates' TS falls 0.44 points on average; creation changes that by 0.22 points per SD, indistinguishable from zero, with no creation x expected-gain interaction. Only ball-handling overlap with the star helps slightly.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedIn sample onlycreation 0.18 TS points per SD; interaction -0.03 (-0.09 to 0.47; -0.21 to 0.19)UA13

When a star's absence raises a teammate's usage, is 'role grew, efficiency held' more common than noise would produce?

No. Absences create real usage jumps (740 rows with +3 usage-rate points vs 283 in random game splits), but 49% keep TS, vs 54% in random splits.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

Not supportedIn sample onlyefficiency held in 49% of real usage jumps vs 54% placebo (placebo counts (90% of 50 draws): jumps 275 to 324, held 148 to 178)UA14

Does Hawk-Eye's "creation leverage" measure creation skill?

No: it ranks players almost exactly as assists per 36 do (rank correlation 0.95); once volume is removed it carries no skill signal.

Not supportedClean nullit ranks players almost exactly as assists per 36 do (rank correlation 0.95)E29

Do the teammates who grab more of a sitting star's usage than predicted keep their efficiency?

Slightly. Split each absence's games in two: the extra share a player grabs beyond prediction in one half correlates r = 0.031 with his TS change in the other half.

Sample: 368 absence events, 308 team-seasons, 4,433 teammate rows; held out = fit 1996-2012, test 2013-2025

SupportedHeld outcross-half r 0.029 (0.009 to 0.048)UA12

Do latent usage and efficiency move in opposite directions within players?

Not in true levels. In a multivariate state-space model, season-to-season changes in true efficiency and true usage correlate +0.32; same-season noise is unrelated (-0.03). The joint model adds no accuracy.

Sample: Full-sample fit

Not supportedIn sample onlyLatent correlation: efficiency~usage +0.32, efficiency~creation +0.32, usage~creation +0.59; noise correlation efficiency~usage -0.03 (0.30 to 0.34 (efficiency~usage latent); -0.07 to 0.01 (noise); 90% jackknife over 10 player groups)SS06

Does creation depend on who feeds the player the ball (pass networks)?

No: feeder dependence moves rank R² from 0.235 to 0.243 (105 players).

Sample: 105 players

Not supportedClean nullfeeder dependence moves rank R² from 0.235 to 0.243 (105 players)T08

Do lucky kick-outs teach a passer better habits?

No sign at the season level: −0.08 kick-rate points per SD of luck (−0.23 to +0.06), against a typical season-to-season change of 2.2.

Not supportedClean null−0.08 kick-rate points per SD of luck (−0.23 to +0.06)T11

Does Durant's teammate shooting lift persist across his career?

Not found: across his career his teammates shot only +0.40 pp above their norms; his multi-season estimate is +0.24 pp, rank 192 of 1,195. His 2024-25 Phoenix figure (+2.73 pp) was mostly luck by this test.

Sample: 18 seasons

Not supportedIn sample onlyDurant multi-season estimate +0.24 pp (rank 192 of 1,195) (about +/-0.34 pp (1 SD))GR04

How should a value metric credit a high-volume scorer whose team needed him to take hard shots?

With a shot model that no longer leaks the result, Kobe's shot diet was harder than average (rank 135 of 602) and he made those shots +2.9 points per 100 above expected (rank 211). His usage credit still depends on the assumed usage cost: rank 25 at the all-player cost, 85 at the creator cost.

Sample: Career shot logs

MixedIn sample onlyKobe usage-credited TS: +7.3 (rank 25) all-player cost, +3.2 (rank 85) creator cost; shot-making +2.92 per 100 (rank 211 of 602), was +0.26 (rank 329) (shot-making +1.81 to +3.97 (90%, game bootstrap); change +2.66 (+2.38 to +2.89))UE05

What do worked examples of role-to-creator jumps show?

Five cases picked by a fixed rule: touch flagged Bane before his record did (+15.5 pull-up points per 100, rough 90% +6.6 to +24.3), raised a false alarm (Murray) and narrowly missed (Podziemski).

MixedIn sample onlytouch flagged Bane before his record did (+15.5 pull-up points per 100, rough +6.6 to +24.3)T09

When a teammate is injured, how much does a player's role grow that night?

Clearly, in the short run (2020-26 game logs, 2,364 player-seasons): per 10 points of assist share freed by injured teammates, assists per 36 rise +0.21 (0.19 to 0.22); per 10 points of usage freed, shots per 36 +0.66 (0.63 to 0.69).

Sample: 2,364 player-seasons; , shots

SupportedIn sample onlyper 10 points of assist share freed by injured teammates, assists per 36 rise +0.21 (0.19 to 0.22)T04

Can a public creation-skill score (θ) stand in for Hawk-Eye shot-making back to 2013?

Partly: θ tracks 2025-26 Hawk-Eye FG% above expected at rank correlation 0.70 (naive version 0.57); walk-forward from 2024-25, 0.60.

MixedHeld outθ tracks 2025-26 Hawk-Eye FG% above expected at rank correlation 0.70 (naive version 0.57)E33

Does our 2015-16 raw-tracking gravity match Hawk-Eye gravity a decade later?

Partly: rank correlation 0.51 (0.25 to 0.70; 30 players). How often a player stands on the perimeter alone matches better (0.66), so location does much of the work.

Sample: 30 players

MixedHeld outrank correlation 0.51 (0.25 to 0.70; 30 players)E34

Does an open creator role predict who becomes a creator?

Tested 2026-10-09 inside the breakout model: removing only the creator-role openings (creation opening, unclaimed creation, heir to the lead creator, lead creator gone) changes next-season creation-jump forecasts by +0.3% (-0.2 to +0.9), not distinguishable from zero. The general roster-opening block helps (BK06); the creator-specific part adds nothing on top.

Sample: 5,439 player-seasons

Not supportedClean nullBrier change without creator-role openings: creation jumps +0.3%; seven types pooled +0.05% (-0.2 to +0.9; -0.17 to +0.28 (90% player bootstrap))U06

Does a player's playoff increase in usage, scoring and minutes repeat?

Yes: usage lift repeats (r +0.184, +0.137 to +0.229), as do points per 75 (+0.103) and minutes (+0.188). Roles repeat; efficiency does not rise with them.

Sample: 3782 player-postseasons, 1061 players; 1924 consecutive pairs

SupportedIn sample onlyusage-lift trait SD 0.89 points of usage; one-postseason reliability 0.125 (SD 0.78 to 1.00; reliability +0.095 to +0.159)RI03

In games a teammate primary creator misses, do the remaining handler's lineups (him the only handler) defend worse than in games all handlers play, beyond the change for lineups with no handler?

Not distinguishable from zero, and not in conflict with RU03: +0.15 (-0.46 to +0.83) on the rerun SiPM. A handler-out night raises a creator's usage only 1.55 points; the one-night cost that survives RU03's checks predicts +0.18 per 100 on such a night. Measured directly for creators (in-season ratings, no garbage time): +0.41 (-0.10 to +0.92).

Sample: 816 handler-team-seasons; 20,884 of 76,399 handler-games with a teammate handler out; placebo 462 team-seasons

Not supportedClean nullLoad-specific change +0.17 points allowed per 100 (current production, re-run 2026-10-10; was +0.15) (90% team-season bootstrap -0.44 to +0.86 (was -0.46 to +0.83))HS05

Does a tracking gravity number put the league's best shooters at the top?

Yes. The 10 leaders in threes made average the 95th percentile (92 to 99); Curry and Korver lead; split-half reliability 0.94.

Sample: 631 SportVU games, off-ball half-court frames

SupportedIn sample onlyTop-10 three-point makers mean percentile 95 (92 to 99 (player bootstrap))VT07

Defense 70

Is there defense a player creates beyond his individual numbers?

Individual numbers explain 26-42% of a player's single-season defensive RAPM. Most of the rest is noise; a small part persists (r 0.19 season to season).

SupportedHeld outIndividual numbers explain 26-42% of a player's single-season defensive RAPME35

Do award votes, including down-ballot ones, carry defensive signal our numbers miss?

All-Defense vote share predicts next season's defensive xRAPM (+0.67, 95% +0.39 to +1.01) even with this season's and 3-season defensive xRAPM in the model. Out of sample the votes remove 0.5% of error (0.15% to 1.0%).

Sample: 8,475 player-seasons; 95% intervals, 2,000 player resamples

SupportedHeld outAll-Defense vote share, with box + measured defense: +0.67 (95% +0.39 to +1.01)AW01

Does a single down-ballot vote carry signal?

A player named by any voter but not selected defends about 0.15 points per 100 better next season than the model expects (95% +0.09 to +0.21), with box score and measured defense controlled.

Sample: 925 cases

SupportedIn sample only+0.15 points per 100 next season (95% +0.09 to +0.21)AW02

Is a single vote noise (e.g. a hometown reporter) while agreement is signal?

Not supported: on published ballots 2014-15 to 2024-25, a single vote predicts as well as several (+0.17 vs +0.17; difference +0.01, 95% -0.16 to +0.17). The test can only detect a gap of about 0.24 or more.

Sample: 125 one-voter, 212 two-plus, 3,021 none

Not supportedClean null2+ voters minus 1 voter: +0.01 (95% -0.16 to +0.17)AW04

Do DPOY votes add beyond All-Defense votes?

DPOY vote share adds nothing once All-Defense share is in the model: -0.22 (95% -0.92 to +0.34).

Sample: 8,475 player-seasons; 95% intervals, 2,000 player resamples

Not supportedClean null-0.22 (95% -0.92 to +0.34)AW03

Do All-Defensive voters lag behind measured defense?

Not against play-by-play defense: lag +0.07 (-0.07 to +0.22).

Not supportedClean nulllag +0.07 (-0.07 to +0.22)E38a

Do All-Defensive voters lag behind measured defense?

Against box-score defense, voters lean on last season: +0.53 (+0.31 to +0.75).

SupportedClean null+0.53 (+0.31 to +0.75)E38b

Does defensive impact decline with age like offense?

Only weakly: measured defensive impact changes little with age (-0.03 a season at 33+, -0.07 to 0.00) while offense falls fast (-0.46). The flat curve may partly reflect a weak measure.

Sample: Delta method

MixedIn sample onlyDefensive change per season at 33+: -0.03 (offense -0.46) (-0.07 to 0.00)TB09

Do defensive breakouts happen young?

Not supported: 33% of defensive breakouts came at 24 or under, against 52% of offensive ones (difference -0.19, -0.30 to -0.09). Median age 25.7 vs 23.9.

Sample: 111 defensive, 109 offensive

Not supportedIn sample onlyShare at 24 or under: defense 33% vs offense 52% (-0.29 to -0.09 (difference))TB08

Do bigs grow more on defense early in their careers?

Both groups rise (bigs +0.068 a season, others +0.040), but the difference is not distinguishable. Gobert looks like a big who arrived early rather than one who improved.

Not supportedIn sample onlyBigs +0.068 vs others +0.040 per season (0.017 to 0.111 (bigs))TB10

Does defense rise more in the playoffs for high-usage creators than for others?

No. Per primary creator on the floor, lineup defense changes -0.21 points per 100 (playoffs vs the same teams' regular season) relative to other players.

Sample: 226,164 playoff possessions per side, 480 playoff team-seasons

Not supportedClean null-0.21 points per 100 per creator on the floor (positive = better defense) (-0.60 to +0.19)PE01

Does a player's defensive playoff lift in one postseason predict the next?

No. Lift in one postseason vs the next: r -0.00; career lifts spread by 2.1 points where noise alone gives 2.1.

Sample: 1349 pairs, 464 players

Not supportedClean nullnext-postseason r -0.00 (1349 pairs) (-0.05 to +0.05)PE03

Does playoff defense beat what regular-season defense predicts for creators?

No. Regular-season defensive xRAPM carries into the playoffs about point for point (slope 0.93); the creator flag adds -0.21 beyond its regular-season value.

Sample: 3,563 player-postseasons

Not supportedClean nullcreator flag, playoffs minus regular season -0.21 (-0.53 to +0.09)PE04

Do public effort proxies rise more for creators in the playoffs?

No. Hustle activity (deflections, contests, loose balls, charges) changes +0.03 SD relative to others; creators move slower on defense (-0.18 SD).

Sample: 809 player-seasons (activity)

Not supportedClean nullactivity index +0.03 regular-season SDs, creators minus others (-0.04 to +0.11)PE05

Do offenses target weak defenders more in the playoffs?

Yes. The weakest fifth by regular-season defensive xRAPM is attacked +0.047 more (target index) than the rest, playoffs vs regular season; in the regular season they are not attacked more.

Sample: 806 defender-seasons, 317 players

SupportedIn sample only+0.047 target index, weakest fifth minus rest (+0.026 to +0.067)PE07

Is the extra hunting costly per attempt?

No. Points per attempt above expected do not rise for weak defenders in the playoffs (slope +0.013 per SD of defense, the wrong sign for a cost).

Sample: 806 defender-seasons

Not supportedClean null+0.013 points per attempt per SD of regular-season defense (+0.007 to +0.019)PE08

Do creators guard tougher or easier players in the playoffs?

Yes. The usage of the man a creator guards, relative to his team, falls 0.51 points more than for others from regular season to playoffs.

Sample: 806 defender-seasons

SupportedIn sample only-0.51 usage points (creators minus others, playoffs minus regular season) (-0.68 to -0.35)PE06

Is lineup defense sub-additive in its players' defensive ratings when an elite anchor is on the floor?

No. Beside a top-5% defender the other four's prior ratings convert 1.06 times as well as elsewhere (90% +0.94 to +1.19); total rating shows no diminishing returns (squared term +0.006). Updated 2026-10-15: was Anchor x other-four interaction +0.03 per rating point (90% −0.09 to +0.16) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 1,879,558 stint sides; about 17 elite anchors a season

Not supportedHeld outAnchor x other-four interaction +0.05 per rating point (90% −0.06 to +0.17)DC01

Within a team-season, does a teammate's on/off defense shrink when an award-recognised anchor plays?

Yes, small: −0.24 points per 100 against comparison pairs (90% −0.37 to −0.10), mostly before 2016-17. Secondary definition; the rating-defined anchors do not show it. Updated 2026-10-15: was Award-anchor pairs minus comparison pairs −0.24 per 100 (90% −0.37 to −0.11) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 2,800 award-anchor pairs

SupportedIn sample onlyAward-anchor pairs minus comparison pairs −0.24 per 100 (90% −0.37 to −0.10)DC03

Is DC03 shooting luck?

Yes. With opponents' threes and free throws at expected rates (SiPM's luck adjustment), the award-anchor interaction is −0.29 per 100 against comparison pairs (90% −0.41 to −0.18), against −0.24 on actual points. Updated 2026-10-15: was Award-anchor pairs minus comparison pairs, luck-adjusted, −0.29 per 100 (90% −0.42 to −0.17) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 2,800 award-anchor pairs, 44,499 comparison pairs

SupportedIn sample onlyAward-anchor pairs minus comparison pairs, luck-adjusted, −0.29 per 100 (90% −0.41 to −0.18)DC09

Within a team-season, does a teammate's on/off defense shrink when the anchor is on the floor?

Not distinguishable from zero: −0.08 points per 100 against comparison pairs (90% −0.19 to +0.04).

Sample: 4,168 anchor pairs, 44,499 comparison pairs

Not supportedClean nullAnchor pairs minus comparison pairs −0.08 per 100 (90% −0.19 to +0.04)DC02

Within player across seasons, does gaining an anchor lower his single-season defensive RAPM?

No, it rises: +0.49 points per 100 from no anchor minutes to all (90% +0.39 to +0.58), within player. Ridge leakage explains +0.37; the remainder +0.10 (90% +0.01 to +0.20) is now just above zero (its 90% interval excludes zero). Updated 2026-10-15: was Anchor share coefficient +0.47 per 100 (90% +0.37 to +0.57) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 9,832 player-seasons, 1,771 players

Not supportedIn sample onlyAnchor share coefficient +0.49 per 100 (90% +0.39 to +0.58)DC04

Does a teammate's target index (attacks vs expected) rise in games the rim anchor plays?

No. With the anchor in, teammates are attacked −2.0% relative to expectation vs −1.2% when a non-elite big is out (difference −0.8%).

Sample: 466 rim-anchor pairs, 4,249 comparison pairs

Not supportedIn sample onlyRim-anchor minus big-comparison, log target index −0.008 (90% −1.7% to 0.1%)DC06

Does any ceiling effect differ before and after 2016-17?

No. From 2016-17 the anchor interaction is −0.08 (90% −0.36 to +0.15) and the pair test −0.02; the award-anchor effect is concentrated before 2016-17. Updated 2026-10-15: was Pair test from 2016-17 −0.03 per 100 (90% −0.20 to +0.17) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 10 later seasons vs 19 earlier

Not supportedClean nullPair test from 2016-17 −0.02 per 100 (90% −0.18 to +0.20)DC08

Do offenses hunt particular defenders, and does defending wear a star down?

Split-half 0.91, season to season 0.66.

SupportedHeld outSplit-half 0.91, season to season 0.66G13a

Do offenses hunt particular defenders, and does defending wear a star down?

Being hunted does not mean being scored on efficiently; Jokic is attacked more than other bigs in most seasons.

Not supportedClean nullBeing hunted does not mean being scored on efficiently; Jokic is attacked more than other bigs in most seasonsG13b

Does measurable length predict defense?

Yes on most declared composites: wingspan and reach beyond height go with better defense for players and teams (intervals such as +0.03 to +0.25); some composites failed their checks.

SupportedIn sample onlywingspan and reach beyond height go with better defense for players and teams (intervals such as +0.03 to +0.25)E41

Among guards, does height go with defense, and does poor shooting cost value?

Guard height shows no link to defensive RAPM (-0.04 per 100 per inch, -0.13 to +0.04); for bigs, +0.21 per inch.

Not supportedClean nullGuard height shows no link to defensive RAPM (-0.04 per 100 per inch, -0.13 to +0.04)E24a

Is a defender's assignment difficulty stable?

The average offensive quality of the players a defender guards repeats (split-half 0.81, next season 0.65). It measures assignment, not success.

Sample: 2,013 rows

SupportedIn sample onlySplit-half 0.81; next season r 0.65TB19

Does the playoff-minus-regular-season defensive lift, read as regular-season coasting, cost teams wins and seeding?

Not supported on public data: the playoff defensive lift (the coasting proxy) is mostly noise, so shrunk per-player costs are a few hundredths of a win (upper spread at most 0.9). As a scenario, a star holding back 0.78 points per 100 all season costs about 0.3-1.3 wins; for Durant's Rockets (one win behind 4th) that is 0.61 home playoff games.

Sample: 372 players, 30 teams; 10,000 simulated postseasons per version

Not supportedIn sample onlyShrunk lift costs <= 0.05 wins per player; scenario +0.78 per 100: named stars 0.34 to 1.31 wins (true spread of lifts 0.19 per 100 (90% upper 0.87); scenario input 0.78 (90% +0.03 to +1.53, in sample))CC06

Do Edwards, LeBron, Giannis, Durant, Doncic, Kawhi and Harden show more playoff defensive lift than the all-player baseline?

Leans yes, fragile. His seven names lift +0.78 points per 100 above the season baseline; luck-adjusted and on-off versions cross zero, and the names were chosen from memory of the same postseasons.

Sample: 3,563 player-postseasons, 969 players

MixedIn sample only+0.78 points per 100 above baseline (7 players, 78 player-postseasons) (+0.03 to +1.53 (90%))SW01

Do rim protectors and defense-first guards and wings (already at maximum effort) show no lift beyond the league shift?

Consistent: B1 lifts +0.16 (-0.17 to +0.49); the test could detect about 0.5. His eight named defenders alone: -1.04.

Sample: 3,563 player-postseasons, 969 players

SupportedIn sample only+0.16 points per 100 (112 players) (-0.17 to +0.49 (90%))SW03

Do weak defenders who always give full effort (Curry, Jokic) show no lift?

Consistent but uninformative: -0.38 (-1.85 to +1.10).

Sample: 3,563 player-postseasons, 969 players

MixedClean null-0.38 points per 100 (2 players) (-1.85 to +1.10 (90%))SW05

Do Tatum and Cunningham show little lift above the baseline?

Not distinguishable: +0.46 (-1.55 to +2.48).

Sample: 3,563 player-postseasons, 969 players

MixedClean null+0.46 points per 100 (2 players) (-1.55 to +2.48 (90%))SW06

Do the two names Griffin flagged as ambiguous show playoff defensive lift?

Leans no: together -1.67 (-3.68 to +0.34); SGA -1.08, Mitchell -2.13.

Sample: 3,563 player-postseasons, 969 players

Not supportedClean null-1.67 points per 100 (-3.68 to +0.34 (90%))SW07

Do very young players, already at full effort, show no lift beyond the league shift?

No: young players lift more than the baseline, +0.38 (+0.03 to +0.73). In-season development may explain it.

Sample: 3,563 player-postseasons, 969 players

Not supportedIn sample only+0.38 points per 100 (480 players) (+0.03 to +0.73 (90%))SW04

Do all 13 named switch-on players together beat the baseline?

Leans yes: +0.71 for 13 players; carries Set 1's in-sample and luck caveats.

Sample: 3,563 player-postseasons

MixedIn sample only+0.71 points per 100 above baseline (13 players, 108 player-postseasons) (+0.06 to +1.36 (90%))SW18

Does the A2 group show lift above the all-player baseline?

Not distinguishable: +0.49; the test could only detect about 2.2 points.

Sample: 3,563 player-postseasons

Not supportedClean null+0.49 points per 100 above baseline (6 players, 30 player-postseasons) (-0.94 to +1.92 (90%))SW15

Does the B2 (Set 2) group show no lift above the baseline?

Consistent but uninformative: -0.90; Flagg and Ball have no qualifying postseason.

Sample: 3,563 player-postseasons

MixedClean null-0.90 points per 100 above baseline (6 players with data) (-3.28 to +1.48 (90%))SW16

A2 minus B2 (Set 2).

Not distinguishable: +1.39.

Sample: 3,563 player-postseasons

Not supportedClean null+1.39 points per 100 (-1.44 to +4.23 (90%))SW17

Does Brown show lift above the baseline?

Not distinguishable: -0.29.

Sample: 3,563 player-postseasons

Not supportedClean null-0.29 points per 100 above baseline (-2.40 to +1.83 (90%))SW19

Is the switch-on list's playoff defensive lift larger than that of calling-card defenders (his named defenders plus guards and wings with prior All-Defensive or DPOY recognition)?

Not distinguishable. A minus B1 = +0.62 points per 100; the test could detect about 1.2.

Sample: 3,563 player-postseasons, 969 players

Not supportedClean null+0.62 points per 100 (-0.20 to +1.44 (90%))SW02

Does the list's lift concentrate in late rounds, game 4 and later, and close series, beyond the baseline's own pattern?

No. Conference finals and Finals vs rounds 1-2: list minus all players -0.54 (-2.23 to +1.15); game 4+ -0.00; close series -0.14.

Sample: 3,563 player-postseasons, 969 players

Not supportedClean nulllate rounds -0.54; game 4+ -0.00; close -0.14 points per 100 (-2.23 to +1.15; -1.66 to +1.66; -2.51 to +2.24 (90%))SW08

Within all players, does series-level defensive lift fall with usage in that series?

No measurable trade-off: -0.14 per 10 usage points (-0.39 to +0.10).

Sample: 6,612 player-series, 951 players

Not supportedClean null-0.14 points per 100 per 10 usage points (-0.39 to +0.10 (90%))SW09

Does lift rise with experience, and is Edwards's lift smaller in his first seasons?

No: +0.007 per season (-0.029 to +0.042). Edwards's later postseasons sit above his early ones at the point estimates, within noise.

Sample: 3,563 player-postseasons, 969 players

Not supportedClean null+0.007 points per 100 per season (-0.029 to +0.042 (90%))SW10

Among starters, do All-NBA or MVP-vote players show more lift, holding rating and usage fixed?

No: visibility coefficient -0.11 (-0.69 to +0.45). Consistent with Griffin's idea that the 'phones it in' story tracks visibility.

Sample: 1,853 player-postseasons

Not supportedClean null-0.11 points per 100 (-0.69 to +0.45 (90%))SW11

Do hustle counts and matchup defense, which do not depend on lineup credit, show the list's playoff lift?

No: hustle activity +0.11 SD (-0.04 to +0.27); matchup points saved -0.36 per 100 (-1.45 to +0.73).

Sample: 801 (hustle), 806 (matchups) player-seasons

Not supportedClean nullactivity +0.11 SD; matchup -0.36 pts/100 (-0.04 to +0.27; -1.45 to +0.73 (90%))SW12

Among team #1 options, is the lift of prior-season plus defenders lower than that of minus defenders?

Reversed: plus defenders lift +0.04, minus defenders -0.91; gap +0.95. Hunting of weak defenders (PE07) may explain it.

Sample: 428 player-postseasons (78 plus, 96 minus players)

Not supportedIn sample onlyplus minus minus +0.95 points per 100 (+0.19 to +1.72 (90%))SW20

Does Davis play more of his playoff possessions as the only big, and is his lift concentrated there?

Unresolved: his center share rises 57% to 63%, but center-minus-other lift +0.40 is far within noise.

Sample: 2923 center and 1695 other playoff defensive possessions

Not supportedClean nullcenter minus other lift +0.40 points per 100 (-5.87 to +6.66 (90%))SW21

Across all bigs, does a larger playoff center share (vs the regular season) go with more lift?

No: +0.11 per 10 points of center share; center minus other lift across bigs +0.30.

Sample: 859 big postseasons, 229 players

Not supportedClean null+0.11 points per 100 per 10 points of center share (-0.10 to +0.31 (90%))SW22

Does one defender embolden his teammates, so they steal more with him on the floor (the Claxton question)?

No sign. The published spillover estimator produces the same spread when nobody affects anybody; a corrected estimator finds nothing beyond noise and team scheme.

Not supportedClean nullNo sign. The published spillover estimator produces the same spread when nobody affects anybody; a corrected estimator finds nothing beyond noise and team ...E36

Does defender pressure lower shooting?

Not identifiable from public data: pressure follows the shooters defenses fear. The most-pressured third beat expected more often (20 of 42 vs 23 of 83; +20 points, 6 to 35).

Not supportedIn sample onlyThe most-pressured third beat expected more often (20 of 42 vs 23 of 83; +20 points, 6 to 35)E31

When did this tactic change in our data, and does that match the told date (2015-16 to 2017-18 (Warriors, then the 2017-18 Rockets))?

Top defender's share of an attacker's matchup possessions in a game fell from about 42% to 33%.

Sample: NBA.com matchups

SupportedIn sample only0.424 in 2017-18 to 0.333 in 2025-26; low point 2025-26; exploratory break before 2021-22 (permutation p 0.016) (last season +0.331 to +0.335 (90%))ET06

When did this tactic change in our data, and does that match the told date (2017-18 / 2018-19 (Rockets in the playoffs); spread since)?

Slope of target index on defensive xRAPM moved from clearly positive toward zero in the regular season; playoffs mostly negative from 2019-20.

Sample: Matchup defender-seasons

MixedIn sample only0.0190 in 2017-18 to 0.0064 in 2025-26; low point 2024-25; exploratory break before 2022-23 (permutation p 0.034) (last season -0.0072 to +0.0193 (90%))ET07

On like-for-like plays, do player speed, distance and closeout measures from tracking data separate effort from skill and role, including regular-season coasting?

Mixed. On 2015-16 SportVU, a like-for-like speed measure (speed above defenders in the same situation) is a stable trait (split-half 0.98; within height groups 0.97) and survives a broadcast-camera simulation (0.99). But it sorts players by position and does not line up with defensive xRAPM (-0.12), so it is not yet shown to be effort.

Sample: 630 games

MixedIn sample onlyLike-for-like effort, split-half reliability 0.98; rank correlation with NBA.com defensive speed (raw) 0.64 (0.98 to 0.99 (352 players); 0.58 to 0.69 (378 players))PE12

In lineup stints, do lineups with 2+ primary creators allow fewer points than the sum of their players' prior-season defensive ratings predicts?

No. The second handler costs about what the first does: L (second's cost minus first's) -0.31 (-0.79 to +0.18) points allowed per 100. Lineups with 2+ handlers allow +0.80 (+0.44 to +1.16) more than their SiPM rating sum, against lineups with none. Updated 2026-10-15: was L (2+ term minus 2.17 x 1-handler term) -0.30 points allowed per 100; 2+ term +0.75 (90% team-season bootstrap -0.79 to +0.18; +0.38 to +1.11) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 1,190,442 defensive stints, 4,201,860 possessions, 540 team-seasons

Not supportedClean nullL (2+ term minus 2.17 x 1-handler term) -0.31 points allowed per 100; 2+ term +0.80 (90% team-season bootstrap -0.79 to +0.18; +0.44 to +1.16)HS01

Within a handler-team-season, is his lineups' defensive residual lower when another primary creator is on the floor?

No. Within player-season, his lineups allow +0.28 (-0.00 to +0.57) more per 100 when paired, about the second handler's own cost. Updated 2026-10-15: was Paired minus alone +0.24 points allowed per 100 (90% team-season bootstrap -0.04 to +0.54) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 1,190 handler-team-seasons with 200+ defensive possessions in each state

Not supportedClean nullPaired minus alone +0.28 points allowed per 100 (90% team-season bootstrap -0.00 to +0.57)HS04

On nights when absent teammates push a player's usage up, do his rebounds and steals per 36 fall, holding fixed the rebounds and steals the absent players free?

No. Per 5 usage points: defensive rebounds +0.04 (-0.02 to +0.08), offensive +0.02 (-0.01 to +0.05), steals +0.01 (-0.01 to +0.04) per 36; none distinguishable from zero.

Sample: 561,831 player-games, 1,782 players; 90% player-cluster bootstrap (400)

Not supportedClean nulldefensive rebounds +0.04 per 36 per 5 usage points (-0.02 to +0.08)RU01

Do blocks and fouls per 36 fall on nights when absences raise a player's usage?

Yes, modestly. Per 5 usage points: blocks -0.04 (-0.05 to -0.02) per 36 (about 5% of the average), fouls -0.13 (-0.16 to -0.10) (about 4%). Shifted-date placebo is zero.

Sample: 561,831 player-games, 1,782 players; 90% player-cluster bootstrap (400)

SupportedIn sample onlyfouls -0.13; blocks -0.04 per 36 per 5 usage points (-0.16 to -0.10; -0.05 to -0.02 (Holm p 5e-09; 0.004))RU02

Within a game, does a player's on-court minus off-court defensive rating worsen on nights when absences raise his usage?

Yes, but smaller than first reported. Raw on-off +2.39 (+1.76 to +2.98) per 5 usage points (2008-09 on); after removing opponents faced, garbage time, in-season rating error and controls, +0.57 (+0.07 to +1.26), all in his on-court minutes. Close-game stints only +0.46 (-0.21 to +1.16), not distinguishable from zero.

Sample: 561,831 player-games, 1,782 players; 90% player-cluster bootstrap (400)

SupportedIn sample only+0.57 opponent points per 100 (on minus off) per 5 usage points, strictest version (90% player bootstrap +0.07 to +1.26; declared residual +1.70 (+1.12 to +2.30))RU03

When a departed or weaker-scoring roster raises a player's usage, do his rebounding, steals, blocks and one-season defensive RAPM fall?

No. With usage pushed up 5 points by falling roster competition: defensive rebounds +0.13 (-0.01 to +0.29), steals -0.02 (-0.07 to +0.03), blocks -0.01 (-0.06 to +0.06) per 36, defensive RAPM -0.14 (-0.39 to +0.12).

Sample: 7,390 pairs, 1,353 players (2,259 after a team change); 90% player-cluster bootstrap (400)

Not supportedClean nulldefensive RAPM -0.14 per 5 usage points (forward) (-0.39 to +0.12)RU04

When a higher-usage teammate arrives and pushes a player's usage down, do his rebounding, steals, blocks and defensive RAPM rise?

No. With usage pushed down 5 points by a higher-usage arrival: defensive rebounds -0.04 (-0.21 to +0.14), steals -0.02 (-0.08 to +0.04), blocks +0.02 (-0.03 to +0.07) per 36, defensive RAPM -0.21 (-0.51 to +0.06). The forward case is also null (RU04), so there is nothing to mirror.

Sample: 7,390 pairs, 1,353 players (2,259 after a team change); 90% player-cluster bootstrap (400)

Not supportedClean nulldefensive rebounds -0.04 per 36 per 5 usage points lost (-0.21 to +0.14)RU05

Over a season, do fouls per 36 fall when roster changes push usage up and rise when they push it down, by the same amount?

Probably. Pooled: -0.12 (-0.17 to -0.06) fouls per 36 per 5 usage points (Holm p 0.001). Forward -0.11 (-0.19 to -0.03) and reverse (usage down 5) +0.13 (+0.02 to +0.22); difference +0.01 (-0.15 to +0.17). Each direction alone misses the declared Holm bar, so symmetry is formally undetermined.

Sample: 7,390 pairs, 1,353 players (2,259 after a team change); 90% player-cluster bootstrap (400)

MixedIn sample onlyforward minus reverse slope +0.01 fouls per 36 per 5 points (-0.15 to +0.17)RU06

When roster changes push a player's usage down, do his screen assists, contested shots and rim contests rise?

Yes in tracking seasons (exploratory, unadjusted). Usage down 5: screen assists +0.38 (+0.14 to +0.59), contests +0.63 (+0.25 to +1.04), shots defended at the rim +0.33 (+0.01 to +0.71) per 36. The forward direction does not show matching drops.

Sample: 2,485 hustle pairs; 1,413 tracking pairs

SupportedIn sample onlyscreen assists +0.38 per 36 per 5 usage points lost (+0.14 to +0.59)RU07

Among players who were creators the season before, does a higher-usage arrival that lowers their usage raise their rebounding or defense?

No. Creators whose usage falls 5 points: defensive rebounds +0.14 (-0.11 to +0.45), defensive RAPM -0.06 (-0.52 to +0.57), steals -0.16 (-0.27 to -0.06) per 36 (steals fall).

Sample: 1,469 creator pairs; reverse first-stage F 41

Not supportedClean nulldefensive RAPM -0.06 per 5 usage points lost (creators) (-0.52 to +0.57)RU08

How much of RU03's one-night on-off cost do the ratings of who was on the floor and the game state explain?

Yes. Of the raw +2.39 per 5 usage points, opponents' ratings explain +0.76 (more minutes against starters) and garbage time about +0.69; 76% of the raw cost goes once those, in-season ratings and controls are removed.

Sample: 345,262 player-games, 1,266 players; 90% player bootstrap (400)

SupportedIn sample onlyopponents' ratings part +0.76; residual +1.70, +0.57 after the added checks (+0.67 to +0.86; +1.12 to +2.30; +0.07 to +1.26)OD01

Do the same defenders close out faster in both halves of the sample?

Moderately. Split-half reliability 0.60 league-wide and 0.40 within height groups; peak speed in closeouts 0.83. Guards close faster than bigs.

Sample: SportVU catch-and-shoot jumpers, contester 6+ ft away at the catch

SupportedIn sample onlySplit-half reliability (Spearman-Brown) 0.60 (0.52 to 0.68 (312 players))VT04

Do reputed elite defenders close out faster than others of their size?

Not found. The 10 All-Defensive players average the 40th percentile of closeout speed above expected within their height group (25 to 53); closeout speed shows no link to defensive xRAPM (0.02).

Sample: SportVU

Not supportedClean nullAll-Defensive mean within-group percentile 40 (25 to 53 (player bootstrap))VT05

Does a defender's speed beyond what his situation demands repeat across games?

Yes, as a trait: split-half reliability 0.98, 0.97 within height groups. Whether it is effort is not shown: it runs slightly against defensive xRAPM (-0.12).

Sample: 631 SportVU games, half-court frames

SupportedIn sample onlyWithin-group split-half reliability 0.97 (0.96 to 0.98 (352 players))VT06

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Defense supplied at least a third of the best 5-year value)

Defense supplied at least a third of the best 5-year value: 5 of 20 in the top 20 vs 34 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

Not supportedIn sample only5 of 20 (top 20) vs 34 of 80 (ranks 21-100)AG09

Availability and injuries 54

How many games will a player miss next season?

Only loosely: out-of-sample R² 0.14 (0.125 to 0.155) vs 0.08 for last season's absences alone; chance of missing 20+ games AUC 0.69 (0.68 to 0.71).

Sample: 15 games

SupportedHeld outout-of-sample R² 0.14 (0.125 to 0.155)T15

Why do players sit, and can injuries be predicted?

Of established players' missed games 2020-26, 56% were injury or illness and 23% coach's decisions. The all-absence forecast predicts benchings; injury games themselves are barely predictable from public history.

Not supportedClean nullOf established players' missed games 2020-26, 56% were injury or illness and 23% coach's decisionsT16

Does a player's injury history sharpen projections?

Walk-forward, injury history improves next season's minutes and games-missed forecasts.

SupportedHeld outWalk-forward, injury history improves next season's minutes and games-missed forecastsT17a

Does a player's injury history sharpen projections?

It does not sharpen the projection of per-minute impact or VORP.

Not supportedClean nullIt does not sharpen the projection of per-minute impact or VORPT17b

Does a player's games-missed history improve the value forecast?

Barely: out-of-sample R² 0.688 → 0.690. The injuries that matter come after the season the model sees (Rose 2011-12: forecast +5.6, actual +0.4).

Not supportedClean nullout-of-sample R² 0.688 → 0.690E21

How much does each kind of injury cost, and does it depend on career stage?

A major injury (21+ games) leaves impact -0.58 per 100 below the pre-injury forecast in the injury season, -0.40 in year 1 and -0.29 in year 2, net of same-age uninjured players. A 10-20 game injury costs -0.10 in year 1.

Sample: 1,892 injury events (926 major, 21+ games), 932 players

SupportedHeld outYear 1 after a major injury: impact -0.40 per 100, role minutes -1.5, value -25 points per 82 (impact -0.51 to -0.28; minutes -1.9 to -1.1; value -30 to -21)U03

Does surgery mark a larger trajectory cost?

Major injuries with surgery: year 1 impact -0.56 per 100 vs -0.28 without (or unknown); value -33 vs -19.

Sample: 1,892 injury events (926 major, 21+ games), 932 players

SupportedHeld outYear 1 impact: surgery -0.56, none/unknown -0.27 (-0.73 to -0.41; -0.39 to -0.15)IE03

Does age at injury change the efficiency cost?

Not among those who play again. Year 1 impact: age 24 and under -0.61, 25-28 -0.38, 29-31 -0.25, 32+ -0.28 per 100. Older players who never return drop out, so this cannot show the old recover better.

Sample: 1,892 injury events (926 major, 21+ games), 932 players

Not supportedHeld out24- -0.60 vs 29-31 -0.24 per 100, year 1 (-0.79 to -0.39; -0.48 to -0.01)IE04

Does the trajectory residual after return differ by injury type and career stage?

Yes. Year 1 after a major injury, impact against the pre-injury forecast: ACL -1.29, Achilles -1.02, other knee -0.56, foot or ankle -0.27, back -0.03 per 100. ACL and Achilles also cut role minutes (-5.5, -3.2). Updated 2026-10-15: the blurb still carried the pre-M1 numbers (ACL -1.30, Achilles -1.07, minutes -5.7 and -3.6); the key effect was refreshed on 2026-10-08 but the blurb was not.

Sample: 1,889 injury events (925 major, 21+ games), 929 players

SupportedHeld outYear 1 impact: ACL -1.29, Achilles -1.02, foot/ankle -0.27 per 100 (ACL -1.78 to -0.86; Achilles -1.60 to -0.42; foot/ankle -0.50 to -0.07 (90%, player bootstrap))AE07

Which injuries change a player's per-minute level?

Half right. ACL and Achilles tears cut per-minute level most (year 1: -1.30 and -1.07 per 100), and ACL's cut lasts past year 2 (-0.91), against a published 'back by year 2'. But other injuries also cut level (other knee -0.55, foot or ankle -0.27), not only games.

Sample: 1,892 injury events (926 major, 21+ games), 932 players

MixedHeld outACL impact year 2 -0.94 per 100; Achilles raw year 1 vs before: minutes -7.1, points -4.2 (published -7.6, -5.4) (ACL year 2 -1.49 to -0.41)U11

Do Achilles and ACL tears need separate treatment?

Return-year impact Achilles -1.07, ACL -1.23; the difference (+0.17) is not distinguishable from zero on impact or games in either year.

Sample: 925 major events; 57 without text left out

SupportedIn sample onlyAchilles minus ACL, return-year impact +0.17 (-0.51 to +0.90 (90%); all four tested intervals include zero)IT03

Should ACL tears be separated from other knee injuries when forecasting the return?

Return-year impact: ACL -1.23, other knee -0.47 per 100; difference -0.76. Games: -16.6 vs -4.9 per 82.

Sample: 925 major events; 57 without text left out

SupportedIn sample onlyACL minus other knee, return-year impact -0.76; games -11.7 (-1.26 to -0.27; games -18.1 to -4.9 (90% player bootstrap))IT02

Beyond location, does the type of injury change the return?

Return-year impact: tear -0.76, fracture -0.16, sprain -0.14, strain -0.40. Tears also cost -1.8 TS points.

Sample: 925 major events; 57 without text left out

SupportedIn sample onlyTear minus fracture, return-year impact -0.60; tear minus sprain -0.62 (-0.94 to -0.26; -1.00 to -0.25 (90%))IT08

Does a major injury predict another, in the same place or anywhere?

26.3% of returners have a new 21+ game injury within two seasons vs 15.6% of healthy same-age players; same subcategory 7.3% vs 1.5%.

Sample: 925 major events; 57 without text left out

SupportedIn sample onlyAny new major injury: excess +10.7 points; same subcategory +5.8 (+8.2 to +13.4; +4.4 to +7.5 (Wilson 90%))IT06

Does a hampered player (e.g. a finger injury) show a shooting dip while playing his minutes?

Across 12,469 played-through games (2018-26), true shooting is not distinguishable from the player's own baseline: -0.002 (95% -0.006 to +0.001). The exception is hand, wrist, finger and thumb listings (IR04).

Sample: 12,469 games, 806 players

Not supportedClean nullTS difference -0.002 (12,469 games, 806 players) (95% -0.006 to +0.001 (bootstrap over players))IR02

Does an upper-extremity injury a player plays through show up in his shooting?

In 945 played-through games with a hand, wrist, finger or thumb listing, true shooting is 1.3 points below the player's own baseline (95% -0.024 to -0.003), while minutes do not change. Ankle and knee listings show no shooting change.

Sample: 945 games, 296 players

SupportedIn sample onlyTS difference -0.013 (945 games, 296 players) (95% -0.024 to -0.003 (bootstrap over players))IR04

Which listed injuries cost shooting efficiency when the player plays?

TS while listed and playing: hand-wrist group -1.3 points, hamstring -1.5, shoulder -1.6, illness -1.0; ankle +0.3, knee +0.3.

Sample: 12,469 games, 806 players

SupportedIn sample onlyHand alone -4.7 TS points; hamstring -1.5; shoulder -1.6 (-7.1 to -2.2; -2.7 to -0.2; -2.9 to -0.4 (90% player bootstrap))IT07

Do listed players who play get their usual minutes?

In played-through games (2018-26) players log about 1 minute below their own baseline: -0.96 (95% -1.15 to -0.76).

Sample: 12,469 games, 806 players

SupportedIn sample only-0.96 minutes (95% -1.15 to -0.76 (bootstrap over players))IR03

Do major hand-area injuries carry into the next season, as knee injuries do?

They do not: return-year impact -0.00, games +0.8 per 82. The cost appears while playing through (IR04).

Sample: 925 major events; 57 without text left out

Not supportedIn sample onlyReturn-year impact -0.00; games +0.8 (-0.28 to +0.26; games -2.5 to +4.1)IT04

Is the baseline's miss on Achilles and ACL returners different from zero?

Yes. Held-out mean miss on value -34.6 points per 82 and games -10.3; the returning-player model cuts them to -3.7 and -0.4.

Sample: 58 held-out Achilles or ACL returning rows

SupportedHeld outValue mean miss -34.6; games -10.3 per 82 (58 rows) (value -46.9 to -22.2; games -14.0 to -6.9 (90% player bootstrap))RP04

How has the season profile of absences changed?

Season regulars who played every game: 20% in 1983-84 to 1999-00, 4% since 2019-20. The one-game share of misses changed little.

Sample: 11,960 player-seasons

SupportedIn sample only19.7% to 3.6%AE06

When a regular misses exactly one game, what is the labeled reason?

Not by the league's labels: of regulars' one-game misses, 18% are labeled rest or injury management, 52% injury, 25% coach's decision. On a back-to-back the rest share is 30%.

Sample: 5,399 one-game misses, 723 players

Not supportedIn sample onlyrest or injury management 18% (90% 16% to 20%)AE02

How restricted are minutes on return, by absence length?

Minutes in the first 3 games back fall from 0.92 of the pre-injury average after 2-4 games out to 0.73 after 20+.

Sample: 13,610 episodes

SupportedIn sample onlymedian ratio after 20+ games 0.73 (90% 0.72 to 0.75)AE05

Do contracts price in serious injuries?

Contracts discount ACL and Achilles injuries (210 deals since July 2021); the trade test (about 25 trades) is too small to show a move.

Sample: 210 deals; 69 trades

SupportedIn sample onlyContracts discount ACL and Achilles injuries (210 deals since July 2021)T19

How much do rookies who lose their first season to injury go on to play?

0.57 of the minutes their draft slot predicts (0.40 to 0.75; 21 players). The asset engine now cuts their minutes, not their per-minute impact, by that ratio.

Sample: 21 players

SupportedIn sample only0.57 of the minutes their draft slot predicts (0.40 to 0.75; 21 players)T18

Does the opening report status add to the returning-player model?

Yes, on 2019-20 to 2025-26 (leave-one-season-out): games squared error 26.8 lower (11.3 to 41.7). Listed Out at the opener: -10.1 games per 82 beyond the model.

Sample: 444 rows, 56 listed Out at the opener

SupportedHeld outGames MSE gain 26.8; value 87.7 (games 11.3 to 41.7; value 5.3 to 193.6)RP05

Among short-season players with an established level, does the cause predict leaving the league?

Yes. Share with no NBA game the next season: trade, waiver or unsigned 63%, coach decision 31%, other major injury 16%, Achilles or ACL 11%.

Sample: 2,059 seasons

SupportedIn sample onlyNo game next season: trade/waiver/unsigned 63% vs injury (other major) 16% (57% to 68%; 13% to 18% (Wilson 90%))RP07

What did games sat by healthy players cost teams in wins, seeding, home playoff games and gate in 2025-26?

Mixed: clean rest codes cost the league about 15 wins and 2.9 home playoff games in 2025-26 ($7.5M of gate); counting every isolated one-game injury miss as rest, 46 wins and 8.1 games. Real but small, concentrated on teams at a seed line.

Sample: 372 players, 30 teams; 10,000 simulated postseasons per version

MixedIn sample onlyLeague total 14.9 to 46.4 wins; 2.9 to 8.1 expected home playoff games; $7.5M to $21.0M gate (bound from the rest classification (low rule to high rule); back-to-back mix puts it near 18 wins; Monte Carlo SE of a team's home games 0.00-0.03)CC01

Did Edwards, LeBron, Giannis, Kawhi, Embiid, Durant, Harden and Doncic lose their teams seeding by sitting healthy?

Not supported except for Embiid: 8 clean rest games cost the 76ers about 0.6 wins and 0.34 home playoff games. Edwards, LeBron, Giannis, Kawhi, Durant, Harden and Doncic sat 0-1 clean rest games; at most 1.1 wins and 0.05 home games under the high rule.

Sample: 372 players, 30 teams; 10,000 simulated postseasons per version

Not supportedIn sample onlyEmbiid 0.60-0.75 wins, 0.34-0.43 home playoff games; the other seven at most 0.05 (low to high rest rule; Monte Carlo SE 0.00-0.02 home games)CC02

Do isolated one-game injury absences behave like rest (back-to-back timing)?

Not supported on this check: clean rest games fall on the second night of a back-to-back 51% of the time, multi-game injuries 18%, isolated one-game injury misses 22%. A mixture reading says about 9% of them are rest.

Sample: 739 short rest-coded games; 4263 isolated misses

Not supportedIn sample onlyBack-to-back share: rest codes 51%, isolated injury misses 22%, multi-game injuries 18%, all games 18% (implied disguised-rest share about 9% (reasoning; mixture assumption))CC05

Does explosive reliance improve forecasts of games missed and exits?

Partly. A more explosive game forecasts fewer games, more so each year past 30: the held-out gain is small but its interval excludes zero (all players 0.88, 0.45 to 1.31; 30+ 1.53, 0.34 to 2.64). It does not help the minutes forecasts or the forecast of who leaves the league.

MixedHeld outGames-played MSE gain 0.88 (age 30+: 1.53); exit log-loss change -0.0007 (0.45 to 1.31; 0.34 to 2.64 (30+); -0.0018 to +0.0003 (exits))TA12

Does a vague label on a long absence signal an unresolved problem?

Games per 82 in the year after the return: -17.6 for major 'contusion or soreness' events vs -4.5 for tears. Added after seeing results.

Sample: 925 major events; 57 without text left out

SupportedIn sample onlyGames per 82, year after: -17.6 (-23.1 to -11.8 (90%))IT09

What does a major back or core injury do to the next two seasons?

Return-year impact +0.01 (no loss); games per 82 -5.1 in the return year and -5.9 the year after.

Sample: 925 major events; 57 without text left out

SupportedIn sample onlyGames per 82, year after -5.9; impact, return year +0.01 (games -11.1 to -1.0; impact -0.31 to +0.33)IT05

When did this tactic change in our data, and does that match the told date (2012-13 (Spurs rest stars); named 2018-19; 65-game award rule 2023-24)?

Core players (28+ mpg) played 95% of roster games in 1983-84 and 77% in 2025-26.

Sample: Player-seasons

SupportedIn sample only0.951 in 1983-84 to 0.771 in 2025-26; low point 2025-26; exploratory break before 2017-18 (permutation p 0.001) (last season +0.743 to +0.798 (90%))ET08

What is the expected cost of each player's missed games next season?

A heavy-minute player is forecast to miss about 21 games to injury; the cost is mostly his value per game. Jokić tops the 2026-27 board at 11.4 wins; the largest Bull is Giddey at 2.7.

Sample: 21 games

SupportedIn sample onlyA heavy-minute player is forecast to miss about 21 games to injuryT21

Do SiPM's misses differ in seasons with injury absences?

A season with 10+ games lost to runs of 2+ missed games falls 0.30 points per 100 further below the SiPM forecast than a clean season. The season after such an injury is not distinguishable from clean (+0.07).

Sample: 4,311 player-seasons, 947 players

SupportedIn sample only-0.30 points per 100 vs clean seasons (-0.39 to -0.21)PM01

Does a player's injury history before the season predict his SiPM miss?

Not supported; it hurts held out: gain -0.0091 (-0.0150 to -0.0018). Inputs: games lost in the two previous seasons, a return flag, and quality x games lost.

Sample: 3,618 scored player-seasons

Not supportedClean nullMSE gain -0.0090 (-0.0149 to -0.0017)PM08

Can injury returns be separated from real breakouts?

A breakout after a season with 30+ games missed that does not beat the player's best healthy season is labelled an injury return and removed. Kevin Love 2013-14 is an injury return on efficiency but still a value surprise; Kawhi 2025-26 an injury return on four dimensions; Lillard 2022-23 is not a breakout.

SupportedIn sample only106 of 117 availability breakouts are injury returnsTB20

How often is a multi-game, non-coach absence of a regular an injury?

81% of such labeled episodes are injury or illness; most of the rest are protocols, G League stints and personal leave.

Sample: 4,350 episodes, 674 players

SupportedIn sample only81% injury or illness (90% 80% to 82%)AE03

How accurate are the rules usable for 1983-2019 (row type, transactions, calendar)?

When the rules call a regular's absence an injury, league labels agree 84% (held-out 2022-23 on) and the injury reports 83% (2018-19 and playoffs). They find only 47% of labeled injuries, because one-game misses are called rest.

Sample: 6,862 labeled episodes

MixedHeld outinjury precision 89%, recall 46% (held out 2022-26) (90% 88% to 90%)AE04

Does multiplying the decayed pre-absence history by (1 + L/10)^-theta (theta fitted per stat) beat the current calendar-day decay on the first 25 games back?

No. Fitted walk-forward, the rate function's exponent sits near zero and changes sign across stats. Held-out per-game error of the 14 SiPM box stats: -0.01%; SiPM box rating +0.09% (worse).

Sample: 4,762 returns, 1,283 players; held out 2,485 returns, 721 players

Not supportedClean nullPer-game error change, 14 box stats pooled -0.01% (reducible -0.08%); box rating 0.00% (was +0.09%); minutes -0.02% (-0.01 to -0.00%; reducible -0.14 to -0.03%; box rating -0.01 to +0.02% (was +0.06 to +0.12%); minutes -0.06 to +0.01% (90% player-cluster bootstrap))LY01

Does keeping the pre-absence estimate, with weight (pre-absence weight) x (1 + L/10)^-theta, beat the current layer on the first 10/25/82 games back?

Mixed. At the return it cuts the first-25-game error of the box stats (-1.59%) and minutes (-15.63%); per game the box stats do not change distinguishably. After 82+ games out it helps box stats (-8.1% of reducible error) and hurts minutes (+47.3%).

Sample: 4,762 returns, 1,283 players; held out 2,485 returns, 721 players

MixedHeld outAt return, first 25 games: box stats -1.59%, minutes -15.63%; per game: box stats reducible -0.33%, minutes reducible -7.39% (-2.39 to -0.73%; -20.40 to -10.27%; -0.74 to +0.12%; -10.89 to -3.11% (90% player-cluster bootstrap))LY02

With one free multiplier per layoff bin, fitted walk-forward, which direction does the data want?

Yes, for box rates (added after). The best multiplier on the decayed history is about 2.0 after 41-81 games out and 3.4 after 82+; held out, 82+ reducible error -5.5%. After short absences it is slightly below 1.

Sample: 4,762 returns, 1,283 players; held out 2,485 returns, 721 players

SupportedReplicated out of sampleReducible error, 14 box stats, games 1-25: all returns -0.81%; 41-81 games out -2.0%; 82+ -5.5% (-1.03 to -0.57%; -3.6 to -0.6%; -8.9 to -1.9% (90% player-cluster bootstrap))LY03

Does the return treatment change SiPM's box rating forecast?

Yes. No method moves its per-game error by more than a fraction of a percent (-0.11% at best). The box model weighs makes against attempts, so a pull toward average volume cancels. Durant: points per 36 fell from 26.2 to 21.0 at the return, box rating +6.43 vs realized +6.18.

Sample: 4,762 returns, 1,283 players; held out 2,485 returns, 721 players

SupportedHeld outBox rating per-game error change: M2 0.00%, M3 +0.06%, M2b +0.01%, M3b +0.10% (was +0.09, +0.06, +0.02, -0.11) (-0.01 to +0.02%; +0.01 to +0.11%; -0.03 to +0.05%; +0.04 to +0.16% (was -0.19 to -0.03% for M3b))LY04

How far below the pre-absence level do returners play in their first 25 games back?

Yes. Against the pre-absence minutes estimate, the first 25 games back average -1.0 minutes for all returns and -6.4 after 82+ games out. Points per 36 after 82+: -0.78, not distinguishable from zero.

Sample: 4,762 returns, 1,283 players; held out 2,485 returns, 721 players

SupportedHeld outMinutes per game minus pre-absence estimate: all -1.01; 41-81 -2.72; 82+ -6.37 (-1.20 to -0.81; -3.51 to -1.98; -7.94 to -4.73 (90% player bootstrap))LY05

Does a pre-absence minutes level scaled by a ratio per layoff length beat the current layer and the unscaled held level on minutes after a return?

Yes. Scaling the pre-absence minutes level by a ratio per layoff length (fitted 1996-2019) cut held-out per-game minutes error after 41+ games out by 5.4%; a planning forecast of the first 25 games (ratio 0.76 after 82+) cut its error 39%.

Sample: Test window 1,399 returns by 462 players (104 after 41+ games out, 26 after 82+)

SupportedHeld outPer-game minutes error games 1-25 vs current (R1): all -3.2%, 41+ -5.4%, 82+ -5.0%; with a ramp (R2) all -4.1%; at-return forecast of first 25 games (R25) 41+ -38.9% (-3.9 to -2.6%; -7.3 to -3.6%; -9.7 to -0.9%; -4.8 to -3.5%; -50.7 to -24.7% (90% player bootstrap; parameters frozen before the test))LY06

After 82+ games out, do box rates come back below the held pre-absence level?

No shift needed in the test window: after 82+ games out, realized points per 36 minus the held level is +0.27 (interval includes zero).

Sample: 26 test returns after 82+ games out

Not supportedClean nullPoints per 36, first 25 games minus held level, 82+ test returns: +0.27 (-0.75 to +1.34 (90% player bootstrap))LY07

Does the direction of the best layoff adjustment depend on whether the decay ages history by calendar days or by games?

Yes. Refit on a player-games clock, the best multiplier on pre-absence history after 82+ games out is 0.27 (Kostya's direction); on calendar days 3.80 (the opposite).

Sample: All 4,762 returns 1996-97 to 2025-26

SupportedIn sample onlyBest multiplier after 41-81 / 82+ games out: calendar days 1.92 / 3.80; league game days 2.15 / 4.05; player games 0.41 / 0.27 (days 2.73 to 5.41; player games 0.37 to 0.47 and 0.23 to 0.35 (90% player bootstrap, refit per draw))LY08

Does a pre-registered clock-speed rule beat the current layer on returns 2020-21 to 2025-26?

Yes, out of sample. Clock speeds 0.61 (41-81 games out) and 0.55 (82+) fitted on 1996-2019 and frozen cut 2020-21..2025-26 reducible error by 7.4% after 41+ games out.

Sample: Test window 1,399 returns by 462 players (104 after 41+ games out, 26 after 82+)

SupportedHeld outReducible error, games 1-25: 41+ -7.4%; 82+ -14.6%; all -0.7%; forecast at return vs first 25, 41+ -13.3% (-9.3 to -5.4%; -18.4 to -11.0%; -0.9 to -0.5%; -17.3 to -8.4% (90% player bootstrap))LY09

How much of the long-layoff gain is the level (pull to average) and how much the learning rate?

Partly. Removing the pull (own-level prior) gets -8.0% of reducible error after 82+ games out vs -14.6% for the clock rule; with the pull gone the clock still wants speed 0.55.

Sample: Test window 1,399 returns by 462 players (104 after 41+ games out, 26 after 82+)

SupportedHeld out82+: O -8.0%, OC -13.7%; clock speed with own prior 0.55 (-12.8 to -2.1%; -18.8 to -7.6%; 0.45 to 0.66)LY11

Does the pre-registered rule improve the season-end projections SiPM's box part reads, scored on next season's box stats?

Yes: next-season box-stat error of season-end projections after a 41+ return falls 2.3%; nobody else's inputs change.

Sample: 304 player-seasons with a 41+ return

SupportedHeld out41+ return in season: -2.3% (2020-21 on -3.8%); 82+: -5.4%; no return: -0.01% (-3.3 to -1.3%; -5.5 to -1.7%; -7.8 to -2.7%; -0.01 to -0.00% (90% player bootstrap))LY12

Does replacing the production minutes forecast for returning players with pre-injury level x a season ratio by layoff length cut held-out error?

No. Inside the production pipeline, the LY06 form forecast next-season minutes per game +32.2% worse (-0.4 to +71.9%) than the production model after 41+ games out, test seasons 2020-21 to 2025-26. Not switched.

Sample: 837 player-seasons (817 with a production forecast); test 57 rows after 41+ games, 273 after 5-40

Not supportedHeld outChange in games-weighted squared error vs production, 41+ games out: S +32.2%; LY06 ratios as fitted +19.1%; 5-40 games out S +21.3% (-0.4 to +71.9%; -5.7 to +54.4%; +6.0 to +39.1% (90%, 1,000 player bootstraps))LY14

Do injury details add to breakout forecasts?

Not supported: removing injury games, major injury and 'ended the season injured' changes next-season breakout forecasts by -0.13% (-0.29 to +0.01), and three-season forecasts by +0.04%.

Sample: Seven types pooled

Not supportedClean nullBrier change without injury inputs: -0.13% (next season), +0.04% (three seasons) (-0.29 to +0.01; -0.13 to +0.21)BK07

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Played 90% or more of the games in the best 5-year run)

Played 90% or more of the games in the best 5-year run: 17 of 20 in the top 20 vs 59 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only17 of 20 (top 20) vs 59 of 80 (ranks 21-100)AG10

Lineups, fit and portability 13

Which player types fit together in lineups?

Next to a star creator, spacers add +0.38 per 100 (0.26 to 0.54) and interior bigs +0.29; a second star creator costs −0.90 (−1.21 to −0.56). 12 of 28 pair cells exclude zero (2.8 by chance), and pair effects fitted on 1996-2013 carry into 2013-26 at 1.19 of their size (0.69 to 1.69).

SupportedReplicated out of sampleNext to a star creator, spacers add +0.38 per 100 (0.26 to 0.54)B18

What fits around Wilson (lineup test)?

Held out one season at a time, a lead creator lifts lineups +1.41 per 100 beyond the ratings (0.75 to 2.07). Shooters −0.23 (−0.53 to +0.05) on a career rule; spacing centers add nothing measurable.

Sample: 27 team-seasons

SupportedHeld outHeld out one season at a time, a lead creator lifts lineups +1.41 per 100 beyond the ratings (0.75 to 2.07)B21

Do switchable defenders make lineups better than their ratings?

Switchability is a stable trait (reliability 0.71). Lineups with more switchable defenders allow 0.28 fewer points per 100 per SD (0.12 to 0.45) than ratings predict, also with prior-season switchability.

SupportedHeld outLineups with more switchable defenders allow 0.28 fewer points per 100 per SD (0.12 to 0.45)B20

Beyond player types, does a specific lineup have its own fit?

Not clearly: lineup-specific fit does not repeat within a season (halves correlate 0.017, −0.010 to 0.048); its spread is at most about 1.9 per 100.

Not supportedClean nulllineup-specific fit does not repeat within a season (halves correlate 0.017, −0.010 to 0.048)B19

Next to the two star types Wilson could become, does any supporting type add a fit bonus?

No: 3 of 16 type cells exclude zero (1.6 by chance), and type effects fitted on 1996-2013 carry into 2013-26 at only 0.18 (−0.05 to +0.34). Even at the top of its interval, fit is worth at most about $9.6M a season, against $18.2M for picking a 75th- over a 25th-percentile player.

Not supportedClean null3 of 16 type cells exclude zero (1.6 by chance), and type effects fitted on 1996-2013 carry into 2013-26 at only 0.18 (−0.05 to +0.34)B22

Does a non-shooting forward star need shooters around him?

The data do not show it: spacers add +0.63 per 100 next to a non-shooting forward star and +1.08 next to a shooting one (difference −0.45, −1.64 to +0.91).

Not supportedClean nullspacers add +0.63 per 100 next to a non-shooting forward star and +1.08 next to a shooting one (difference −0.45, −1.64 to +0.91)B23

Does how a player's impact changes with teammate quality depend on age?

At 22 and under, each point of teammate quality lowers a player's apparent impact by 0.125 per 100 (-0.168 to -0.078); by 25-27 the effect is near zero.

Sample: 7,028 rows

SupportedIn sample onlyImpact change per point of teammate quality, age 22-: -0.125 (-0.168 to -0.078)TB15

Can a player's impact with stronger vs weaker teammates be measured as his own trait?

Not at the player level: a player's portability score does not repeat (split-half 0.11, next season r 0.04). Griffin agreed to drop it as a per-player label and keep the league-level pattern (TB15).

Sample: 7,028 rows

Not supportedIn sample onlyNext-season r 0.04; split-half 0.11TB14

When did this tactic change in our data, and does that match the told date (2014-15 / 2015-16 (Warriors' small lineups))?

Share of team minutes with no player 82 in+ held at 10-15% until 2016-17, doubled by 2020-21, then eased.

Sample: Lineup stints

SupportedIn sample only0.093 in 1996-97 to 0.250 in 2025-26; halfway 2018-19; exploratory break before 2018-19 (permutation p 0.001) (last season +0.241 to +0.261 (90%))ET04

When injuries force lineup changes, does fit around a Wilson-type forward show up?

No: 0 of 19 trait comparisons exclude zero against a plain teammate's absence (which itself costs −0.41 per 100, −0.71 to −0.15). The lead creator: +2.6 (−0.3 to +5.4), consistent with B21.

Not supportedClean null0 of 19 trait comparisons exclude zero against a plain teammate's absence (which itself costs −0.41 per 100, −0.71 to −0.15)B24

Do lineups with 2+ primary creators score less than a straight-line sum of the first handler's lineup effect?

Yes. 1 handler scores +2.11 (+1.75 to +2.46) beyond the offensive rating sum, 2+ +2.82 (+2.35 to +3.27); the second adds much less than the first (L -1.77 (-2.27 to -1.24)). Larger since 2021-22. Updated 2026-10-15: was L -1.76 points scored per 100 (2+ term minus 2.17 x 1-handler term) (90% team-season bootstrap -2.27 to -1.23) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 1,190,442 defensive stints, 4,201,860 possessions, 540 team-seasons

SupportedIn sample onlyL -1.77 points scored per 100 (2+ term minus 2.17 x 1-handler term) (90% team-season bootstrap -2.27 to -1.24)HS03

Holding a player's box profile at fixed prices, does a traditional center (6-10+, under 10% threes) add more to lineup margin in 2021-26 than in 2014-21?

Not under the declared rule. Lineups gain +0.24 points per 100 more per traditional center in 2021-26 than in 2014-21 (90% −0.43 to +0.95), beyond the value of his box line. 2025-26 alone is high (+2.67 to +5.10).

Sample: 1,314,446 stint sides, 18 seasons, 540 team-season clusters

Not supportedClean null+0.24 points per 100 per TC on the floor (recent minus mid) (−0.43 to +0.95 (90%, team-season bootstrap))CV01

Holding box profile fixed, does any 6-10+ big add more to lineup margin in 2021-26 than in 2014-21?

Mixed. Any listed 6-10+ big adds +0.90 more per 100 in 2021-26 (90% +0.40 to +1.38), but the height-free rebounding non-shooter type does not (−0.02), and listed heights drift across the 2019 re-measurement (CV08).

Sample: 1,314,446 stint sides

MixedIn sample only+0.90 points per 100 per BIG (recent minus mid) (+0.40 to +1.38 (90%, team-season bootstrap))CV05

Stars, titles and team building 74

Does a champion need a star creator?

Teams with one won 32 titles where the bracket-aware odds expected 26.7 (1980-81..2025-26); odds x1.86 (1.12 to 3.18); series odds x1.55 (1.24 to 1.93).

Sample: 46 seasons, 724 team-seasons, 678 series

SupportedHeld outTitle odds x1.86 for star-creator teams (1980-81..2025-26); series odds x1.55 (1.12 to 3.18; series 1.24 to 1.93)B03

Does a smooth weight in usage rank and relative true shooting tie or beat the yes/no star-creator flag on hits and halve its rank jumps?

Title equity with the soft weight beats the yes/no flag on All-NBA (+1.1 points, +0.4 to +2.0) and top option on a playoff team (+1.3, +0.4 to +2.4); a 1-point shooting change moves no top-30 player 10+ places (flag: 34 of 570). Rule D: adopt.

Sample: 4718 player-seasons, 18 seasons; 19 boards for stability

SupportedHeld outAll-NBA top-30 hit rate +1.1 points vs the flag; rank jumps 34 to 0 (+0.4 to +2.0)BR05

Does the best soft weight on a roster predict champions better than the yes/no flag?

Held-out champion log loss 1985-86..2025-26: soft 1.583 vs gate 1.691; difference -0.109 (-0.192 to -0.022).

Sample: 41 champions

SupportedHeld outChampion log loss, soft minus gate -0.109 (-0.192 to -0.022)BR06

Does a premium fitted on 1980-2008 forecast 2008-26 series better than the bracket odds alone?

The premium replicated (x1.56 fitted early, x1.64 refitted late) but the out-of-sample log-loss gain is not distinguishable from zero (-0.0055, -0.0195 to +0.0097). Rule C fails; the test passes only 33% of the time if the premium is real.

Sample: 270 test series, 131 with a star-creator difference

MixedHeld out2008-26 series log loss, premium minus base -0.0055; late refit x1.64 (-0.0195 to +0.0097; refit 1.12 to 2.54)BR03

Does the true-shooting condition in B03's star-creator flag carry information beyond high usage?

On held-out champions the gate does not beat the same flag without it (-0.051 to +0.006 log loss), so the declared rule renames the premium a lead-option (usage) premium. At series level the gate does help (-0.0064, -0.0119 to -0.0010).

Sample: 46 champions, 678 series; 82 team-seasons where the flags differ

MixedHeld outHeld-out champion log loss, gate minus no gate -0.024; series -0.0064 (-0.051 to +0.006; series -0.0119 to -0.0010)BR01

Does B03's premium disappear when team strength is built from SiPM forecasts corrected for the creator under-forecast?

Correcting creators' SiPM forecasts walk-forward moves star-creator teams by +0.009 points; the premium moves from x1.81 to x1.75. The declared rule fired (interval includes 1), but real margin on the same 18 seasons also includes 1.

Sample: 18 seasons, 270 series

Not supportedHeld outTitle premium under SiPM+LR03 strength x1.75; correction shift for star teams +0.009 points (0.47 to 9.29; series x1.56 (1.09 to 2.43))BR02

Is the star-creator premium different in the three-point era (2016-17 on)?

Series odds x1.53 before 2016-17 and x1.67 after; difference in log-odds +0.09 (-0.54 to +0.88). No change detectable.

Sample: 36 vs 10 seasons; 528 vs 150 series

Not supportedClean nullLater minus earlier, series log-odds +0.09 (-0.54 to +0.88)BR04

Can role-player teams win titles?

Yes, less often than their margins suggest: 13 of 45 champions lacked a star creator under the declared rule; such teams won 13 titles where their odds implied 19.0.

SupportedIn sample onlyChampions without one entered at 1.41× the odds of star champions (0.97 to 2.08)B04

Do teams with two star creators win more titles than their margins predict?

In sample, yes: 18 titles vs 10.9 expected (+7.1, +3.6 to +10.7). On fresh seasons (1980-81 to 1995-96), 3 titles vs 2.6 expected without a premium and 5.3 with it: not replicated (only 16 two-star playoff teams).

Not supportedNot replicated18 titles vs 10.9 expected (+7.1, +3.6 to +10.7)B06

Does a team's playoff edge rise with how high its best creator ranks in usage?

Not measurably: +0.61 points per game from no creator to the league's top creator (−0.21 to +1.53).

Not supportedClean null+0.61 points per game from no creator to the league's top creator (−0.21 to +1.53)B05

Does team strength built from players (rating × expected playoff minutes) beat margin at predicting champions?

Yes: log loss 1.458 vs 1.651 on 29 seasons the models did not see (−0.361 to −0.032). Still too flat at the top (calibration slope 1.49).

Sample: 29 seasons

SupportedHeld outlog loss 1.458 vs 1.651 on 29 seasons the models did not see (−0.361 to −0.032)B08

Does simulating the real playoff bracket predict champions better than regular-season margin?

Yes: log loss 1.63 vs 1.74 for margin alone, each season predicted by a model fitted without it (difference about −0.11; 90% −0.20 to −0.03 in the 10-01 run).

SupportedHeld outlog loss 1.63 vs 1.74 for margin alone, each season predicted by a model fitted without it (difference about −0.11; −0.20 to −0.03 in the 10-01 run)B01

Does adding February 21 rosters improve the trade-deadline title forecast?

Yes: champion log loss 1.440 vs 1.482 (−0.070 to −0.013), better in 8 of 10 seasons.

Sample: 10 seasons

SupportedHeld outchampion log loss 1.440 vs 1.482 (−0.070 to −0.013)B09

How did the 2025-26 forecast do?

At the end of the regular season the Thunder were 48%; the champion Knicks 4.5% (5th-highest); on February 21, 4.6% (5th). One champion cannot validate a probability model.

SupportedIn sample onlyAt the end of the regular season the Thunder were 48%B10

How well can public data rank who becomes All-NBA (the star baseline)?

Age, BPM, scoring and usage per 36, draft slot and minutes give average precision 0.587 on 26 future stars (1,523 rows). The baseline under-forecasts its top bands by +7, +10, +5 and +11 points.

Sample: 26 future stars

SupportedHeld outAge, BPM, scoring and usage per 36, draft slot and minutes give average precision 0.587 on 26 future stars (1,523 rows)S01

Is the star baseline getting worse as more is priced in?

No: average precision 0.30 (1988-89), 0.44 (1990s), 0.47 (2000s), 0.60 (2010s). With a fixed training window and a box composite that is not BPM, the edge over draft slot still grows.

Not supportedHeld outaverage precision 0.30 (1988-89), 0.44 (1990s), 0.47 (2000s), 0.60 (2010s)S02

Is the star baseline calibrated at the top?

No, too low: players forecast 65%+ made All-NBA 94% of the time. A Platt correction fixes the level (top observed/expected 1.20 → 1.04; Flagg 85% → 91%, 84 to 95), but no correction that reorders the list beat the plain one on later seasons.

SupportedHeld outA Platt correction fixes the level (top observed/expected 1.20 → 1.04; Flagg 85% → 91%, 84 to 95)S07

Where do #1 options come from?

Of 114 star creators since 1979-80: 46 were top-3 picks, 37 picks 4-10, 23 picks 11-30, 8 second-rounders; 70% of their star seasons came on the team that drafted them (Gilgeous-Alexander is the acquired-as-prospect route).

SupportedIn sample onlyOf 114 star creators since 1979-80S20

When do #1s arrive, and who stands beside a #2?

#1s first reach the role in a median year 4 (69-91% by year 5); 78-85% are still with their first team. The #1 beside a #2 was older in 66-73% of cases and a top-10 pick in 66-71%.

SupportedIn sample only#1s first reach the role in a median year 4 (69-91% by year 5)S26

Does style uniqueness ("singularity") predict All-NBA?

No. It changes average precision by −0.039 (it slightly hurts); a learned style embedding does worse.

Not supportedClean nullIt changes average precision by −0.039 (it slightly hurts)S03

Does rare skill for size flag the next singular star?

No. None of 22 declared comparisons excludes zero once models are refit in every draw (about 1.1 each way by chance).

Not supportedClean nullNone of 22 declared comparisons excludes zero once models are refit in every draw (about 1.1 each way by chance)S04

Do rare combinations of skills for size flag future stars?

No: 0 of 16 tests clear zero either way (0.8 expected each way by chance); real combinations do no better than shuffled ones.

Not supportedClean null0 of 16 tests clear zero either way (0.8 expected each way by chance)S05

Are there two kinds of stars, and do models miss the singular kind?

62% of All-NBA seasons show breadth. "Singular only" seasons are as common among All-NBA players (11%) as among near-stars (10%).

Not supportedClean nullModel under-rating of singular players is not distinguishable (+0.06, −0.09 to +0.21; 47 rows)S06

Which grounded ranking best predicts the outcomes a 'best player' ranking should predict?

Top 30 by title equity made All-NBA 37.6% of the time vs SiPM 34.6% (+3.0 points, +1.7 to +4.3 points) and were a playoff team's top option 30.2% vs 26.3% (+3.9, +2.6 to +5.2 points). Updated 2026-10-15: was All-NBA top-30 hit rate +2.2 points vs SiPM (+1.5 to +3.0 points) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 4,718 player-seasons, 18 seasons; season bootstrap 2,000

SupportedHeld outAll-NBA top-30 hit rate +3.0 points vs SiPM (+1.7 to +4.3 points)LR05

Does SiPM after pricing the efficiency cost of a lead-role usage load predict best-player outcomes better?

Not supported. The lead-role rating's top 30 made All-NBA 34.1% of the time (-0.6 points vs SiPM, -2.0 to +0.9 points); no best-player outcome improves. Updated 2026-10-15: was All-NBA top-30 hit rate -0.9 points vs SiPM (-2.0 to +0.4 points) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 4,718 player-seasons, 18 seasons; season bootstrap 2,000

Not supportedClean nullAll-NBA top-30 hit rate -0.6 points vs SiPM (-2.0 to +0.9 points)LR06

Does subtracting each UE02 type's 31st-best rating (supply) improve a best-player ranking?

Not supported: worse. Top-30 All-NBA hit rate -0.9 points vs SiPM (-1.9 to -0.0 points); salary rank correlation 0.44 vs 0.53. Updated 2026-10-15: was All-NBA top-30 hit rate -1.9 points vs SiPM (-3.0 to -0.9 points) before the 2026-10-07 SiPM re-run; numbers refreshed from the current output.

Sample: 4,718 player-seasons, 18 seasons; season bootstrap 2,000

Not supportedClean nullAll-NBA top-30 hit rate -0.9 points vs SiPM (-1.9 to -0.0 points)LR07

Does evaluating the title-equity model at a player's demonstrated role capacity (usage and minutes) instead of his current role improve a best-player ranking?

Not supported. R5 (title equity at the largest load carried in the last three seasons with impact held) put 38.1% of its top 30 on All-NBA vs R2's 37.6% (+0.6 points, -0.4 to +1.5); top option on a playoff team +0.9 (-0.4 to +2.0). Updated 2026-10-15: was All-NBA top-30 hit rate +0.9 points vs R2 (+0.0 to +1.9) before the re-runs after 2026-10-08 (SiPM reruns and the ordered re-run of 2026-10-09/10); numbers refreshed from the current output.

Sample: 4,718 player-seasons, 18 seasons; season bootstrap 2,000

Not supportedClean nullAll-NBA top-30 hit rate +0.6 points vs R2 (-0.4 to +1.5)RC01

Is absence of lead-load evidence some evidence of absence: do first-time lead-load seasons hold less often?

Supported in sample. Their first lead-load seasons hold (impact within 1 point per 100 of their lower-load level) 86% of the time vs 95% for players who carried one before (-9 points, -15 to -3).

Sample: 70 first-time and 292 repeat rows; player bootstrap 2,000

SupportedIn sample onlyHeld rate -9 points (first-time minus repeat) (-15 to -3)RC04

Within a player-team-season, does a higher share of team plays (usage x minutes) caused by teammate absences lower his lineups' margin beyond the other nine players' ratings?

Not supported. Instrumented by absent teammates' load, impact changes +0.01 points per 100 per load point (-0.04 to +0.06); the naive slope is +0.54.

Sample: 701,124 player-games, 2,188 players; player bootstrap 2,000

Not supportedClean null+0.01 points per 100 per load point (-0.04 to +0.06)RC02

Does the per-possession cost of extra load depend on how much load the player already carries?

Mixed. By the season's load band the instrumented slope is <10%: +0.16, 10-15%: -0.09, 15-20%: -0.14 (-0.27 to -0.02), 20-25%: -0.07, 25%+: -0.11 (wide).

Sample: 701,124 player-games, 2,188 players; player bootstrap 2,000

MixedIn sample only15-20% band: -0.14 points per 100 per load point (-0.27 to -0.02)RC03

Is SiPM's forecast too high for players handed their first lead load?

Not supported. At a first lead load the residual vs SiPM's walk-forward forecast is +0.34 vs +0.45 for repeat lead players (difference -0.12, -0.52 to +0.30).

Sample: 70 first-time and 292 repeat rows; player bootstrap 2,000

Not supportedClean null-0.13 points per 100 (first-time minus repeat) (current production, re-run 2026-10-10; was -0.12) (-0.52 to +0.31 (90%; was -0.52 to +0.30))RC05

Do the top usage creators (B03 rule) defend better in the playoffs than their regular season predicts?

Leans yes but not distinguishable from zero: +0.21 points per 100 per star creator on the floor; the regular-season-to-playoff residual test gives +0.39.

Sample: 226,164 playoff possessions per side, 480 playoff team-seasons

Not supportedClean null+0.21 points per 100 per star creator (lineup test); +0.39 (player test) (-0.29 to +0.72; -0.01 to +0.77)PE02

Does offense rise more in the playoffs for creators?

No: +0.02 points per 100 per creator on the floor. Griffin's contrast (offense cannot be switched on) holds, but defense does not switch on either.

Sample: 226,164 playoff possessions per side, 480 playoff team-seasons

Not supportedClean null+0.02 points per 100 per primary creator (-0.37 to +0.42)PE09

What separates future #1s from #2s before they arrive?

Growth, not shooting accuracy: future #1s add free-throw attempts per 36 and xRAPM faster under all three definitions (e.g. FTA/36 +0.45 per year, +0.17 to +0.71, earlier run).

SupportedIn sample onlyfuture #1s add free-throw attempts per 36 and xRAPM faster under all three definitions (e.g. FTA/36 +0.45 per year, +0.17 to +0.71, earlier run)S27

Does a champion need a top-5 player?

21 of 30 champions since 1996-97 had one (70%, 55 to 82%): more often than not. They won 21 titles where their odds implied 16.7 (range 12 to 21), so a premium beyond the player's rating is not established.

Not supportedClean null21 of 30 champions since 1996-97 had one (70%, 55 to 82%)B07

How often does the team with the better regular season lose a series?

27% of series (24 to 30%); a margin gap of 6 to 8 points still loses 13% of the time. 663 series, 1980-2025.

Sample: 663 series

SupportedIn sample only27% of series (24 to 30%)B02

How much does each player add to his team's title odds (championship probability added, CPA)?

Gilgeous-Alexander about 43 points with a replacement rule (38 to 48), about 48 (34 to 61) with the lineup model; depth players on deep teams are worth far less than a replacement rule says.

SupportedIn sample onlyGilgeous-Alexander about 43 points with a replacement rule (38 to 48)B11

Does resembling an all-time great at 19-23 predict a star?

No: 85 box-score-era greats fall into 10 weakly stable shapes, and resemblance adds nothing to an All-NBA forecast (average precision −0.000, −0.006 to +0.005).

Not supportedClean null85 box-score-era greats fall into 10 weakly stable shapes, and resemblance adds nothing to an All-NBA forecast (average precision −0.000, −0.006 to +0.005)S29

In January 2016, could public tracking have flagged the future stars?

No: adding 4 pre-declared movement features dropped average precision from 0.41 to 0.30 (change −0.21 to +0.05); 12 future All-NBA among 285 players. Updated 2026-10-15: was adding 4 pre-declared movement features dropped average precision from 0.42 to 0.29 (change −0.22 to +0.002) before the 2026-10-01 re-run chain; numbers refreshed from the current output.

Sample: 285 players

Not supportedClean nulladding 4 pre-declared movement features dropped average precision from 0.41 to 0.30 (change −0.21 to +0.05)S10

Does a head coach's effect travel to his next team?

Barely: a coach's result beyond the roster at his old teams predicts his next team's at slope 0.07 (−0.09 to +0.23); the portable effect is at most about 1.1 points per 100 (90% upper bound).

Not supportedClean nulla coach's result beyond the roster at his old teams predicts his next team's at slope 0.07 (−0.09 to +0.23)O16

Do an executive's past trades predict his next ones?

No: r −0.02 (−0.17 to +0.13), split by date within each executive's record (pick values not counted).

Not supportedClean nullr −0.02 (−0.17 to +0.13)O17

Does the star-creator bonus help a pre-season ranking pick who adds the most on-court playoff margin, on a label with no usage in it?

Not supported. On a usage-free playoff outcome, title equity's top 30 hit 29.8% vs margin added 30.6% (-0.7 points, -1.7 to +0.2). Rule written before the run: within 1 point, so the bonus is a column, not a rank input.

Sample: 4,718 player-seasons, 18 postseasons, 3,817 player-postseason labels; season bootstrap 2,000

Not supportedClean nullTop-30 hit rate 0.0 points vs margin added (SiPM x minutes) (was -0.7) (-0.7 to +0.7 points (90%; was -1.7 to +0.2))PO01

How much is the star-creator flag worth on the usage-free playoff label, beyond margin added?

Not supported (added after the declared test). Across the pool, with a smooth curve in margin added, the flag is worth +0.37 points of margin added (-0.04 to +0.88), below the 1.27 title equity adds.

Sample: 4,718 player-seasons, 18 postseasons, 3,817 player-postseason labels; season bootstrap 2,000

Not supportedIn sample only+0.37 points of margin added (flag) (current production, re-run 2026-10-10; was +0.37) (-0.06 to +0.88 (90%; was -0.04 to +0.88))PO06

Does pricing players at their demonstrated role capacity pick better playoff performers than margin added?

Not supported. R5's top 30 hit 30.9% vs margin added 30.6% (+0.4 points, -0.7 to +1.5); within 1 point, so a column, not a rank input.

Sample: 4,718 player-seasons, 18 postseasons, 3,817 player-postseason labels; season bootstrap 2,000

Not supportedClean nullTop-30 hit rate +0.2 points vs margin added (SiPM x minutes) (was +0.4) (-1.5 to +1.7 points (90%; was -0.7 to +1.5))PO02

Does the usage part of the star flag, on its own, pick better playoff performers?

Not supported. Margin added plus the bonus for any 28+ minute top-15 usage player hit 30.0% vs 30.6% (-0.6 points, -1.5 to +0.6).

Sample: 4,718 player-seasons, 18 postseasons, 3,817 player-postseason labels; season bootstrap 2,000

Not supportedClean nullTop-30 hit rate -0.6 points vs margin added (SiPM x minutes) (-1.9 to +0.7 points (90%; was -1.5 to +0.6))PO04

Which sort key, rate or rate x minutes, better picks next-season playoff performers?

Not separated. Margin added minus SiPM: -0.2 points of top-30 hit rate (-1.1 to +0.6). The sort stays where earlier evidence put it (margin added, on All-NBA average precision).

Sample: 4,718 player-seasons, 18 postseasons, 3,817 player-postseason labels; season bootstrap 2,000

Not supportedClean nullTop-30 hit rate -0.7 points vs margin added (SiPM x minutes) (was -0.2) (-2.6 to +1.1 points (90%; was -1.1 to +0.6))PO03

Does a team-level decomposition of margin into P2's eight parts beat net rating alone at predicting held-out playoff games and series?

No. Held out one season at a time, the model with the eight parts (weights shrunk toward their regular-season values) changes playoff game error by -0.15 squared points per game (-1.03 to +0.66) and series log loss by -0.0025 (-0.0104 to +0.0049). Under the declared rule two parts still pass the weight test (TOV, DSHOT), both as playoff discounts.

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullheld-out game error vs net alone -0.15 squared points per game (-1.03 to +0.66 (90%, resampling held-out seasons))PD01

Beyond net rating, does a point of margin from avoiding turnovers pay differently in playoff games?

Passes the declared rule: beyond net rating it pays 0.62 points per point less in the playoffs (difference -0.62, -0.96 to -0.21), and passes within both eras. It fails the eight-test correction and adds nothing held out.

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

MixedIn sample onlyplayoff minus regular-season weight, beyond net rating -0.62 points per point (-0.96 to -0.21 (90%, season bootstrap))PD02

Beyond net rating, does a point of margin from holding opponents' shooting down pay differently in playoff games?

Passes the declared rule beyond net rating (-0.25, -0.47 to -0.03), but within eras only from 2016-17 on. As a total weight it grows in the playoffs as much as net rating (0.98x, added after), so this is not evidence that defense is worth less per point.

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

MixedIn sample onlyplayoff minus regular-season weight, beyond net rating -0.25 points per point (-0.47 to -0.03 (90%, season bootstrap))PD03

Does a point of margin from unassisted half-court scoring pay more in playoff games?

No. Playoff minus regular-season weight, beyond net rating: +0.01 (-0.13 to +0.15).

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullplayoff minus regular-season weight, beyond net rating +0.01 points per point (-0.13 to +0.15 (90%, season bootstrap))PD04

Does a point of margin from free throws drawn pay differently in playoff games?

No. Playoff minus regular-season weight, beyond net rating: -0.25 (-0.47 to +0.01). Passes within one era only (before 2016-17), an era-specific candidate.

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullplayoff minus regular-season weight, beyond net rating -0.25 points per point (-0.47 to +0.01 (90%, season bootstrap))PD05

Does a point of margin from threes pay differently in playoff games?

No. Playoff minus regular-season weight, beyond net rating: -0.09 (-0.19 to +0.03).

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullplayoff minus regular-season weight, beyond net rating -0.09 points per point (-0.19 to +0.03 (90%, season bootstrap))PD06

Does a point of margin from offensive rebounding pay differently in playoff games?

No. Playoff minus regular-season weight, beyond net rating: -0.25 (-0.64 to +0.14). Passes within one era only (from 2016-17), an era-specific candidate.

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullplayoff minus regular-season weight, beyond net rating -0.25 points per point (-0.64 to +0.14 (90%, season bootstrap))PD07

Does a point of margin from forced turnovers pay differently in playoff games?

No. Playoff minus regular-season weight, beyond net rating: -0.26 (-0.66 to +0.14).

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullplayoff minus regular-season weight, beyond net rating -0.26 points per point (-0.66 to +0.14 (90%, season bootstrap))PD08

Does a point of margin from defensive rebounding pay differently in playoff games?

No. Playoff minus regular-season weight, beyond net rating: -0.01 (-0.68 to +0.70).

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

Not supportedClean nullplayoff minus regular-season weight, beyond net rating -0.01 points per point (-0.68 to +0.70 (90%, season bootstrap))PD09

Does a point of regular-season net rating buy more margin in playoff games than in regular-season games between playoff teams?

Yes, as a by-product of this test. Between playoff teams, a point of net-rating gap buys +0.75 points of regular-season margin (that game left out) and +1.19 of playoff margin (difference +0.44, +0.27 to +0.60).

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

SupportedIn sample onlynet-rating slope, playoffs minus regular season +0.44 (with the eight parts in the model) (+0.27 to +0.60 (90%, season bootstrap))PD10

Does a net-rating model with round-specific weights predict held-out playoff series better than one weight for all rounds?

Mixed, found after seeing results. From 2016-17 on, letting net rating's playoff weight differ by round improves held-out series log loss by -0.0172 (-0.0267 to -0.0072); pooled 1996-2025 it does not (-0.0036).

Sample: 2,440 playoff games, 450 series, 30 seasons; 9,912 regular-season games between playoff teams

MixedHeld outseries log loss vs one weight, 2016-17 on -0.0172 (-0.0267 to -0.0072 (90%))PD11

Do broad college producers, or the best combine athletes, become #1s?

Broad producers became #1s 12-13% of the time vs 1-2% (not adjusted for draft slot).

SupportedIn sample onlyBroad producers became #1s 12-13% of the time vs 1-2% (not adjusted for draft slot)S28a

Do broad college producers, or the best combine athletes, become #1s?

The top 10% in combine athleticism for height did not: 2-5% vs 4-6%.

Not supportedClean nullThe top 10% in combine athleticism for height did notS28b

Measured only where all-out speed pays (fast breaks he leads), does speed for size mark future stars?

Suggestive only: 4 of 9 tests exclude zero; elite-for-height players became first-time All-NBA 7.4% vs 3.7% (2 of 27 players). Some stars could not be measured (Kyrie had 3 such breaks in the window, while returning from injury).

Sample: 27 players

MixedIn sample only4 of 9 tests exclude zeroE27

Do teams that beat their regular season in the playoffs do it again?

No sign: next-postseason r +0.063 (-0.019 to +0.136) over 1983-2026. One postseason's team residual is about 2% team; a repeating team edge above about 1.1 points per game is ruled out.

Sample: 688 team-seasons; 508 consecutive pairs

Not supportedClean nullnext-postseason r +0.063 (508 pairs) (-0.019 to +0.136 (franchise-cluster bootstrap, 90%))B16

Do champions carry more SLAP-lite (measurable frame and combine athleticism)?

No: champions' top-8 rotations carry no more than other playoff teams (−0.01, −0.09 to +0.06, earlier run), and SLAP-lite adds nothing to title odds beyond margin.

Not supportedClean nullchampions' top-8 rotations carry no more than other playoff teams (−0.01, −0.09 to +0.06, earlier run)B25

What was one more point of margin worth at the 2026 deadline?

8.1 title points to the Thunder and 6.3 to the Pistons; to the Bulls, 1.1 points of playoff odds and no title odds (playoff odds 48% even at +10 per game).

SupportedIn sample only8.1 title points to the Thunder and 6.3 to the PistonsB12

Was Jokić visible in January 2016?

The baseline model ranked him 43rd of 285 (his draft slot weighed on him). Judged against his age, experience and slot he was 5th (2nd among 48 players 22 and under).

Sample: 48 players; 12 stars

SupportedIn sample onlyThe baseline model ranked him 43rd of 285 (his draft slot weighed on him)S11

Do the definitions of a "#1" and a "#2" agree?

No: 51-58 #1s and 49-73 #2s among 1,360 players drafted 1996-2018, depending on the definition; the definitions agree on only 50-69% of each other's #1s.

Sample: 1,360 players

Not supportedIn sample only51-58 #1s and 49-73 #2s among 1,360 players drafted 1996-2018, depending on the definitionS21

Recent playoff upsets come from the play-in and rested stars making regular-season records less telling?

Not supported. Upsets by record rose +10.3 points; strength from star games or the game-1 roster does not remove a measurable part, and play-in series had fewer upsets (7 of 31).

Sample: 663 series; 75 recent

Not supportedIn sample onlyRise in upset share +10.3 points; removed by star-games rating -0.0, by roster at series start +5.1, by SRS + roster +2.3 (rise +1.4 to +20.5; removals -7.0 to +8.0, -4.4 to +13.8, -6.0 to +10.1 (90%))ET-U2

Does a continuous star-creator weight beat margin added on the usage-free playoff outcome?

Not supported. Margin added plus the soft lead-creator bonus (b03-refit's declared soft measure) put 30.4% of its top 30 in the next postseason's top 30 vs 30.6% for margin added (-0.2 points, -1.3 to +0.7): within 1 point, so a column, not a rank input.

Sample: 4,718 player-seasons, 18 postseasons; season bootstrap 2,000

Not supportedClean nullTop-30 hit rate -0.2 points vs margin added (-1.3 to +0.7 points (90%))PO07

How closely does regular-season level predict playoff level?

Yes: playoff box production tracks regular-season production at correlation 0.82 (slope 0.88); playoff level repeats next postseason at r 0.67.

Sample: 3782 player-postseasons, 1061 players; 1924 consecutive pairs

SupportedIn sample onlycorrelation 0.825, slope 0.875 (Game Score per 75) (playoff level next postseason r +0.631 to +0.709)RI04

Do the best regular-season players rise or fall relative to others in the playoffs?

Yes: the top 5% by regular-season Game Score per 75 change -0.74 (-1.19 to -0.35) relative to the typical player, with true shooting -1.16, while taking more usage.

Sample: 210 top-tier player-postseasons, 58 players

SupportedIn sample only-0.74 Game Score per 75 (top 5% tier) (-1.19 to -0.35)RI05

How much of a great playoff record is a playoff-specific edge?

Yes, on the example Griffin raised: Jordan ranks 2 of 294 in playoff box production per possession, but his lift above the typical playoff drop is +1.10 raw and +0.45 after shrinkage.

Sample: 259 players

SupportedIn sample onlyJordan career lift +1.10 raw (noise SE 0.60), shrunk +0.45 (posterior SD 0.41; most generous trait size +0.58)RI08

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (A top-15 season (by total value) by age 22)

A top-15 season (by total value) by age 22: 15 of 20 in the top 20 vs 19 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only15 of 20 (top 20) vs 19 of 80 (ranks 21-100)AG03

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (A top-15 season within his first three seasons)

A top-15 season within his first three seasons: 18 of 20 in the top 20 vs 49 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only18 of 20 (top 20) vs 49 of 80 (ranks 21-100)AG04

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Ten or more top-15 seasons)

Ten or more top-15 seasons: 18 of 20 in the top 20 vs 10 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only18 of 20 (top 20) vs 10 of 80 (ranks 21-100)AG07

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Won a title inside the best 5-year run)

Won a title inside the best 5-year run: 12 of 20 in the top 20 vs 21 of 80 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only12 of 20 (top 20) vs 21 of 80 (ranks 21-100)AG11

Draft and prospects 61

Does the draft order beat a public pre-draft model, and why?

On four-year value the draft wins 57% of disagreements (52 to 64), 63% (55 to 71) when it separated players by 10+ picks. Once both players reached 1,000 minutes: 46% (42 to 52), and on per-minute impact the model wins 58%. Updated 2026-10-15: was On four-year value the draft wins 56% of disagreements (51 to 62) before the 2026-10-01 rebuild; numbers refreshed from the current output.

SupportedHeld outOn four-year value the draft wins 57% of disagreements (52 to 64)S19

Which college stats carry to the NBA, and does any beat draft slot?

Within position, 3PA rate, block %, offensive rebound % and steal % carry best (r 0.64 to 0.72); 3P% barely (0.26). No college number predicts NBA value beyond slot out of sample (0 of 15 cells).

Not supportedClean nullWithin position, 3PA rate, block %, offensive rebound % and steal % carry best (r 0.64 to 0.72)S16

Does a rookie's box score beat the draft order at spotting future All-NBA players?

Clearly in 4 of 6 decades (1960s, 1970s, 2000s, 2010-16; e.g. 2000s 0.52 vs 0.32 average precision), not in the 1980s or 1990s. Each decade is fit only on earlier classes.

MixedHeld outClearly in 4 of 6 decades (1960s, 1970s, 2000s, 2010-16S12

Does the box-score model beat what teams learned from the same rookie season (their year-2 minutes)?

Only in 1 of 6 decades. Teams' minutes also use practice, scouting and medical files.

Not supportedHeld outOnly in 1 of 6 decadesS13

Does a rookie season help say who becomes a #1 or #2?

Brier better in 3 of 5 definitions; impact definition +0.020 (0.007 to 0.029).

SupportedHeld outimpact definition +0.020 (0.007 to 0.029)S24a

Do an executive's past drafts predict his next ones?

Yes: r 0.32 (0.11 to 0.53); 0.33 (0.11 to 0.54) after removing how good the team was before the draft.

SupportedHeld outr 0.32 (0.11 to 0.53)O18

Can draft slot and age tell a future #1 from a future #2?

Mostly no: AUC 0.49 (option definition), 0.54 (impact), 0.60 (All-NBA tier, the one definition where they separate). The test had 80% power to see 0.69-0.71.

Not supportedClean nullAUC 0.49 (option definition), 0.54 (impact), 0.60 (All-NBA tier, the one definition where they separate)S22

Counting only contenders, can slot and age tell a #1 from a #2?

No under the main version: AUC 0.44 (0.31 to 0.57). 3 of 14 versions separate (about 1 expected by chance).

Not supportedClean nullAUC 0.44 (0.31 to 0.57)S23

Does a rookie season help say who becomes a #1 or #2?

It barely separates #1s from #2s: the AUC gain excludes zero in only one definition.

Not supportedClean nullIt barely separates #1s from #2sS24b

Does age at the draft sharpen the draft-day forecast?

Younger draftees become All-NBA more often (top-10 picks: 30% of the youngest third vs 15% of the oldest), but on unseen classes adding age does not measurably improve log loss (−0.002, −0.009 to +0.004).

Not supportedClean null30% of the youngest third vs 15% of the oldest), but on unseen classes adding age does not measurably improve log loss (−0.002, −0.009 to +0.004)S14

Did the prep-to-pro and one-and-done eras change what age means?

No: age × era terms change out-of-sample R² by −0.0002 (−0.003 to +0.002).

Not supportedClean nullage × era terms change out-of-sample R² by −0.0002 (−0.003 to +0.002)S15

Do recruiting rankings add anything?

No: the recruit score adds nothing beyond slot (−0.007 R², −0.018 to +0.003). AAU and high-school stats are not public in usable form.

Not supportedClean nullthe recruit score adds nothing beyond slot (−0.007 R², −0.018 to +0.003)S17

Do college free throws or combine drills better predict NBA shooting?

College FTs beat drills for NBA FT%: +0.25 (+0.07 to +0.42).

SupportedHeld out+0.25 (+0.07 to +0.42)S30a

Do college free throws or combine drills better predict NBA shooting?

For threes the drill leans ahead but cannot be separated: -0.30 (-0.75 to +0.12).

Not supportedClean null-0.30 (-0.75 to +0.12)S30b

How do EuroLeague and other leagues translate?

A EuroLeague scorer keeps about 78% of his points per 40; domestic leagues and the EuroCup 69-72%. For international draftees, production adds nothing beyond slot (a weak test).

SupportedIn sample onlyA EuroLeague scorer keeps about 78% of his points per 40S18

Do late picks playing far above their slot (draft-slot flags) become stars more often?

In sample, yes: 27% vs 21% expected, which met the declared rule. Out of sample it adds nothing.

Not supportedNot replicated25% vs 30% expected (−5.3 points, −17.9 to +7.6)S09

What path would Wilson need to become a #1?

Among 6'8"-6'10" forwards, every #1 path needs more usage by years 4-5: +3.5 to +6.9 points from his projected 21% start (15.6 to 26.5); 4-15% of players his age made that move.

SupportedIn sample only+3.5 to +6.9 points from his projected 21% start (15.6 to 26.5)S32

Did players built like Wilson reach #1 or #2 at their slot's rate?

Less often (option 2 vs 5.0 expected; impact 1 vs 3.7; All-NBA tier 3 vs 5.8), but a shortfall this size happens 8-12% of the time by chance.

Not supportedClean nullLess often (option 2 vs 5.0 expectedS33

What does Wilson's body say?

For his height he jumps higher than 94-98% of combine participants and is quicker than 79-81%, but lighter than 90% and shorter-armed than 69%.

SupportedIn sample onlyFor his height he jumps higher than 94-98% of combine participants and is quicker than 79-81%, but lighter than 90% and shorter-armed than 69%S34

Which college seasons look most like Wilson's?

Murray-Boyles, Sullinger, G. Williams, Simmons, Zeller, Draymond Green, W.

SupportedIn sample onlynone became a high-volume, efficient #1 scorerS35

What does Bryson Graham's draft record show?

His front offices took players about where ESPN's board ranked them (the test catches only large reaches). Against same-slot picks, his picks differ on no combine part (composite +0.31; p 0.20; Holm 1.00).

Not supportedClean nullAgainst same-slot picks, his picks differ on no combine part (composite +0.31O20

Do draft slot and age at entry explain SiPM's misses in career seasons 1-4?

Not supported held out: gain -0.0031 (-0.0073 to 0.0011). SiPM has no draft input, and the persistent misses continue years after the draft (Jokic, Hill).

Sample: 3,618 scored player-seasons

Not supportedClean nullMSE gain -0.0031 (-0.0073 to 0.0011)PM06

Do rookies' preseason box stats improve a forecast of their rookie-season impact beyond draft slot and age?

Over 463 rookies with 500+ minutes (2008-09..2025-26, walk-forward), shrunk preseason per-36 rates cut squared error by 0.25; correlation with rookie impact rises 0.24 to 0.39.

Sample: 463 rookies

SupportedHeld outMSE change -0.249 (impact points squared; base 2.79) (-0.42 to -0.06)PS04

Does a draft-slot curve forecast rookie-season value better than the average rookie?

Yes. A curve in log pick, fitted on earlier rookie classes, removes 10.4% of the squared error of the rookie average (R^2 0.10). Production has no next-season forecast for players without NBA minutes.

Sample: 2,097 rookies

SupportedHeld outError removed vs the rookie mean: +10.4% (+3.7 to +16.8% (90%, player bootstrap))DP06

Does weighting recent rookie classes (or adding an era term) remove the high bias for picks 1-20 without losing the gain over the rookie average?

No. Weighting recent classes (half-life chosen walk-forward) changed rookie forecast error by -0.1% (-1.1 to +0.9%); an era trend -0.0% (-0.8 to +0.9%). The picks 4-10 gap is real, but fixing it costs as much at picks 1-3. Production keeps the pooled curve, plus a monotone hold past pick 40.

Sample: 2,097 rookies, 25 first-season classes

Not supportedClean nullSquared error removed vs the pooled curve, all rookies: recency -0.10%; era trend -0.01% (-1.1 to +0.9%; -0.8 to +0.9% (90%, class bootstrap, 2,000))DP08

Do public college numbers improve a draft-slot forecast of peak SiPM in years 2-5, on classes the model has not seen?

Yes: slot + 38 college and combine inputs remove +10.1% of the slot's squared error on peak SiPM, walk-forward over 11 classes; better in 9 of 11. Updated 2026-10-15: was +9.9% of slot squared error removed (MSE 2.874 to 2.589) (+3.5% to +15.8% (90%, players); +2.4% to +16.8% (classes)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

SupportedHeld out+10.1% of slot squared error removed (MSE 2.985 to 2.684) (+3.4% to +16.1% (90%, players); +2.2% to +17.5% (classes))CP01

Do college numbers improve a draft-slot forecast of reaching 15+ minutes per game in a season of years 2-5?

No: -0.005 log loss per player; the college model alone is clearly worse than the slot (-0.057). Minutes follow the slot.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedClean nulllog loss change -0.0046 per player (base rate 55%) (-0.0252 to +0.0154 (90%))CP02

Do college numbers improve a draft-slot forecast of a top-60 SiPM season (1,000+ minutes) in years 2-5?

Yes, modestly: log loss +0.024 per player, AUC 0.747 to 0.778; better in 9 of 11 classes.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

SupportedHeld out+0.0228 log loss reduction per player (current production, re-run 2026-10-10; was +0.0240) (+0.0013 to +0.0427 (90%; was +0.0042 to +0.0437))CP03

Without the draft order, how close does a public college model come to the market?

Mixed: on peak SiPM it ties the slot (+2.7%); among players who earned minutes it beats it (+15.1%); on rotation it is clearly worse. Updated 2026-10-15: was Peak SiPM +3.2%; top-60 log loss +0.017; rotation -0.057 (-6.2% to +11.1%; -0.007 to +0.042; -0.087 to -0.026 (90%)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

MixedHeld outPeak SiPM +2.7%; top-60 log loss +0.015; rotation -0.057 (-7.2% to +11.1%; -0.009 to +0.040; -0.087 to -0.026 (90%))CP04

Where in the draft does the college model add to the slot?

Picks 1-14: +31.9% of slot error removed on peak SiPM; picks 15-30 -0.3%; 31-60 -0.3%. Updated 2026-10-15: was Picks 1-14: +31.2% (n 131) (+19.5% to +41.1% (90%, players)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

SupportedHeld outPicks 1-14: +31.9% (n 131) (+20.9% to +42.2% (90%, players))CP05

Which college inputs carry the model's gain over slot?

BPM alone with slot removes +11.6% of peak-SiPM error; dropping it from the full model costs +7.4%. Career BPM outweighs final-season BPM; a final-season jump is marked down. Updated 2026-10-15: was add to slot +11.9%; drop from full +7.7% (+7.0% to +16.3%; +4.3% to +10.6% (90%)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

SupportedHeld outadd to slot +11.6%; drop from full +7.4% (+6.6% to +15.9%; +4.1% to +10.3% (90%))CP06

Does age at the draft improve a draft-slot forecast of peak SiPM out of sample?

No: adding age at the draft to draft slot changes peak-SiPM squared error by -1.5% (-4.2% to +0.9%). Its weight inside the full model is in the heterogeneity field. Updated 2026-10-15: was add to slot -1.1%; drop from full model +2.5% (-3.6% to +1.3%; -1.2% to +6.5% (90%)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedClean nulladd to slot -1.5%; drop from full model +1.6% (-4.2% to +0.9%; -2.2% to +5.5% (90%))CP07

Does steal % and block % improve a draft-slot forecast of peak SiPM out of sample?

On their own, yes (+5.0%); once BPM is in the model they add nothing (+0.0%): BPM already holds them. Updated 2026-10-15: was add to slot +4.2% (+1.3% to +6.8% (90%); beyond the full model -0.9% to +1.0%) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

SupportedHeld outadd to slot +5.0% (+2.0% to +7.6% (90%); beyond the full model -0.9% to +0.8%)CP08

Does college free-throw shooting improve a draft-slot forecast of peak SiPM out of sample?

No: adding college free-throw shooting to draft slot changes peak-SiPM squared error by +0.3% (-1.1% to +1.8%). Its weight inside the full model is in the heterogeneity field.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedClean nulladd to slot +0.3%; drop from full model +0.1% (-1.1% to +1.8%; -0.7% to +1.0% (90%))CP09

Does college assist rate improve a draft-slot forecast of peak SiPM out of sample?

No: adding college assist rate to draft slot changes peak-SiPM squared error by +0.7% (-0.7% to +2.0%). Its weight inside the full model is in the heterogeneity field. Updated 2026-10-15: was add to slot +0.5%; drop from full model +0.4% (-1.3% to +2.2%; -0.1% to +1.0% (90%)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedClean nulladd to slot +0.7%; drop from full model +0.4% (-0.7% to +2.0%; -0.2% to +1.0% (90%))CP10

Does combine size, length and athletic tests improve a draft-slot forecast of peak SiPM out of sample?

No: adding combine size, length and athletic tests to draft slot changes peak-SiPM squared error by -1.1% (-3.5% to +1.0%). Its weight inside the full model is in the heterogeneity field. Updated 2026-10-15: was add to slot -1.8%; drop from full model -1.2% (-4.0% to +0.3%; -2.2% to -0.2% (90%)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedClean nulladd to slot -1.1%; drop from full model +0.2% (-3.5% to +1.0%; -1.3% to +1.8% (90%))CP11

When the model and the pick order rank two classmates differently, whose ranking does the outcome follow?

Mixed: the 10% the model liked most beat their slot's expectation by +0.53 SiPM and the 10% it liked least fell short by -0.78; but over all opposite-ranked pairs the draft is right 53%.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedHeld outpick right in 55.8% of opposite-ranked pairs (long sample, 5,033 pairs) (52.6% to 59.1% (90%, classes))CP12

Do non-linear trees find interactions the linear model misses?

No: trees did worse than the ridge model on all three outcomes (peak SiPM -12.3% vs the linear model). Updated 2026-10-15: was peak SiPM: trees' squared error +11.8% vs the linear model's (+5.2% to +18.6% (90%)) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedHeld outpeak SiPM: trees' squared error +12.3% vs the linear model's (+6.1% to +18.9% (90%))CP13

Is a public pre-draft board a better market benchmark than the pick?

No: on peak SiPM the board ties the slot (+0.6%); on rotation it is worse. The college model adds as much to the board (+10.1%) as to the slot. Updated 2026-10-15: was peak SiPM +0.1% (-4.1% to +4.3% (90%); rotation -0.044 to -0.004) before SiPM rerun 2 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes; 90% intervals from 2,000 player bootstraps unless noted

Not supportedClean nullpeak SiPM +0.6% (-3.9% to +5.0% (90%); rotation -0.044 to -0.004)CP14

Can the model, applied to all college seniors, flag undrafted players who later earn NBA minutes?

Partly: a college model trained on draftees puts 17 of 53 undrafted future rotation players inside its top 60 of their class; ranking by college BPM alone finds about as many.

Sample: 53 undrafted rotation players in test classes; 342 undrafted NBA players matched by name

SupportedHeld outAUC 0.957 for rotation among 14,892 undrafted players; top 50 per class holds 60% of them (AUC 0.946 to 0.972 (90%, classes))CP16

Does a translated international profile forecast NBA impact beyond slot, as college numbers do?

Partly: international box scores translated to a college scale and scored by the college model sharpen the top-60 forecast for international draftees (+0.113 log loss) but the scale runs high: they finish -0.69 xRAPM below the college model's forecast.

Sample: 89 test players

MixedHeld outtop-60 log loss +0.113; peak xRAPM +10.2% (+0.032 to +0.214; -5.6% to +22.9% (90%, players))CP17

Is the high reading for picks 4-10 in recent classes larger than class-to-class noise?

Yes. In first seasons 2013-25, picks 4-10 averaged 5.3 value points against a walk-forward forecast of 28.61; 10 of 13 classes fell short. Not noise.

Sample: 91 rookies, 13 classes

SupportedHeld outMean gap, actual minus walk-forward forecast, picks 4-10, first seasons 2013-25: -23.3 value points (-33.0 to -13.6 (90%, class bootstrap))DP09

Is the drop in first-season value of picks 4-10 a change in rookie roles (minutes) or in rookie play (impact per minute)?

Yes, in sample. Picks 4-10: impact per 100 possessions changed -0.97 (2013-25 vs 1996-2012); minutes changed -131 (interval spans zero). With the early impact, recent value would be 24.91 instead of 5.3.

Sample: 91 rookies 2013-25; 119 in 1996-2012

SupportedIn sample onlyChange in minute-weighted impact, picks 4-10, 2013-25 minus 1996-2012: -0.97 (-1.43 to -0.54 (90%, class bootstrap))DP10

Can a pre-debut version forecast first-three-season breakouts and arrivals better than draft slot alone?

Tested: for arrivals in the first 1-3 NBA seasons, slot + college BPM is no better than slot alone (starter level within 3 seasons: -0.0004 log loss, -0.0164 to +0.0141). The 2026 draftees' arrival rows are written for the breakout board anyway.

Sample: 864 players (starter, 3 seasons); 6 outcome x horizon cells

Not supportedHeld out-0.0004 log-loss reduction per player (starter level within 3 seasons, slot + BPM vs slot) (-0.0164 to +0.0141 (90%, players))BK11

Is the scouting rule 'trust his free throws' right for accuracy?

R^2 for 3P% at 25-27: FT% 0.12, 3P% 0.09, both 0.18. The FT-over-3P gap is not distinguishable from zero. Updated 2026-10-15: was FT% minus 3P% models, R^2: +0.034 (-0.079 to +0.151) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 206 players with a 25-27 3P%

MixedHeld outFT% minus 3P% models, R^2: +0.030 (-0.082 to +0.147)WB06

Does free-throw shooting predict who starts shooting threes?

Among the third of young players who took the fewest threes, FT% at 19-21 explains 0.12 of threes per 36 at 25-27; their 3P% explains -0.09.

Sample: 72 low-volume players

SupportedHeld outLow-volume third, R^2 of later 3PA per 36 from FT%: 0.12 (0.01 to 0.20)WB07

Once a player has played, does his draft slot still tell you about his traits?

Adding draft slot to the 19-21 values never improved the 25-27 forecast in 31 traits; for three-point volume it hurt (-0.164). Updated 2026-10-15: was Three-point attempts per 36, R^2 change from adding draft slot: -0.167 (-0.324 to -0.043) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: Walk-forward; outcome at ages 25-27; 1,000 player resamples

Not supportedHeld outThree-point attempts per 36, R^2 change from adding draft slot: -0.164 (-0.320 to -0.042)WB08

Which profile at 19 returns the most value beyond draft slot and early production?

Adding the explosive-versus-skill profile to draft + production changes the R^2 of value at 22-27 by -0.012; the shooting profile by +0.002.

Sample: Value = points above replacement per 82 games, summed over ages 22-27, 0 when not playing

Not supportedHeld outValue at 22-27, R^2 gain from the shooting profile: +0.002 (-0.030 to +0.030)WB09

Should the draft board use free throws as a three-point-volume signal?

Yes: college FT% adds +2.6% (+1.4% to +3.9%) to slot + BPM + college threes for NBA three-point volume in years 2-5; +4.9% in years 5-7.

Sample: 619 players (years 2-5), 435 (years 5-7)

SupportedHeld out+2.6% of squared error (NBA 3PA per 36 vs league, years 2-5) (+1.4% to +3.9% (90%, players))WB12

Does a two-number college model (BPM, final and career) plus slot match the 38-input model out of sample?

Yes: slot + college BPM (final and career) removes +11.9% of slot error on peak SiPM; the 38-input model +10.1%; adding four more inputs changes nothing (+0.1%). Updated 2026-10-15: was +12.2% of slot squared error removed (slot + BPM) (+7.8% to +16.5% (90%, players)) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes

SupportedHeld out+11.9% of slot squared error removed (slot + BPM) (+7.6% to +16.0% (90%, players))CP18

On the same test classes, does a model fitted from 1995 beat the same model fitted from 2008?

No measurable gain: fitting from 1995 instead of 2008 changes peak-xRAPM error on 2011-2021 classes by +1.3%.

Sample: 971 test players, 22 classes

Not supportedHeld out+1.3% of squared error (peak xRAPM) (-1.1% to +3.7% (90%, players))CP19

Does the gain survive removing the players who contribute most to it?

Supported for slot + BPM: dropping the 20 players it helped most (of 524) still leaves +4.0%; dropping them and the 20 it hurt most leaves +9.9%. Updated 2026-10-15: was +10.1% after symmetric trimming of 20 + 20 players (+5.8% to +14.6% (90%, players, trimming redone per draw)) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes

SupportedHeld out+9.9% after symmetric trimming of 20 + 20 players (+5.8% to +14.4% (90%, players, trimming redone per draw))CP20

Is the gain smaller in recent draft classes, as if teams have learned the college signal?

Not supported: slot + composite gains by era are 2000-05 +5.7%, 2006-10 +2.5%, 2011-15 +5.3%, 2016-21 +1.4%, with overlapping intervals.

Sample: 971 test players, 22 classes

Not supportedHeld out2016-21 +1.4% vs 2000-05 +5.7% (2016-21 -3.3% to +5.9%; 2000-05 +1.2% to +9.7%)CP21

Does the team's rating (or schedule strength) add beyond BPM, which already adjusts for opponents?

Not distinguishable from zero: +1.4% on peak SiPM; schedule strength -0.3%. Updated 2026-10-15: was +1.3% of squared error (-0.9% to +3.5% (90%, players)) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes

Not supportedHeld out+1.4% of squared error (-0.9% to +3.6% (90%, players))CP22

Does college usage add beyond BPM?

No: -0.4% on peak SiPM. Updated 2026-10-15: was -0.3% of squared error (-1.0% to +0.4% (90%, players)) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 524 test players, 11 classes

Not supportedHeld out-0.4% of squared error (-1.1% to +0.3% (90%, players))CP23

Does a public scouting rank add information beyond the pick and college BPM?

No: adding ESPN's final board rank changes peak-SiPM error by -1.6%; the bar an eye-test grade must clear. Updated 2026-10-15: was -1.2% of squared error (-6.2% to +3.4% (90%, players)) before SiPM rerun 3 (2026-10-09); numbers refreshed from the current output.

Sample: 520 players

Not supportedHeld out-1.6% of squared error (-6.8% to +2.8% (90%, players))CP24

Is it true of the top 20 by sustained peak, and more than of ranks 21-100? (Drafted in the top 3 (players with a recorded pick))

Drafted in the top 3 (players with a recorded pick): 10 of 19 in the top 20 vs 27 of 76 in ranks 21-100.

Sample: Top 100 by sustained-peak score (top 20 vs ranks 21-100)

SupportedIn sample only10 of 19 (top 20) vs 27 of 76 (ranks 21-100)AG08

Does slot + a BPM with possessions, team-mates' shares and a team-rating adjustment beat slot + college-2's composite out of sample?

Not measurably: slot + the new BPM +4.2% of slot error on peak xRAPM vs +3.7% for the old composite; difference +0.6% (-1.7% to +2.5%).

Sample: 971 test players, 22 classes; outcome peak xRAPM years 2-5

Not supportedHeld out+0.6% of the old model's squared error (new BPM vs old composite, both with slot) (-1.7% to +2.5% (90%, players); classes -1.3% to +2.3%)CP28

Does college FT% add to college 3P% and volume when forecasting NBA 3P%?

Yes: added to slot + BPM + college threes, FT% removes +5.8% (+2.7% to +8.7%) of the error on NBA 3P% (years 2-5); +6.6% (+2.0% to +10.9%) in years 5-7.

Sample: 477 players (years 2-5), 337 (years 5-7)

SupportedHeld out+5.8% of squared error (NBA 3P% vs league, shrunk, years 2-5) (+2.7% to +8.7% (90%, players))CP30

Do college shooting signals (FT%, FT rate, threes) add to slot + BPM for peak impact?

No: FT% added to slot + BPM -0.3% (-0.8% to +0.1%) on peak xRAPM; college threes -0.3%.

Sample: 971 test players

Not supportedHeld out-0.3% of squared error (peak xRAPM, years 2-5) (-0.8% to +0.1% (90%, players))CP31

On the board's own target, does slot + Barttorvik BPM beat slot + the rebuilt team-page BPM?

On the 500 college draftees of 2011-2021 with both, slot + Barttorvik BPM (final and career) removes +4.0% more of the squared error of peak xRAPM (NBA years 2-5) than slot + the rebuilt BPM (+1.5% to +6.3%, 90% players). Same direction as CP27/the +5.0% on peak SiPM.

Sample: 500 players

SupportedHeld out+4.0% of squared error (peak xRAPM years 2-5; Barttorvik minus rebuilt BPM, both with slot) (+1.5% to +6.3% (90%, players); classes +0.9% to +6.6%)CP33

Markets, trades and cap 33

Can players and picks be priced in one currency (the asset engine)?

Yes, as a yardstick: one VORP costs about $14.4M on today's market; a #4 pick returns about $56M more than it costs. Projections tie a linear model 1-2 seasons ahead and beat it 3-4 ahead (+0.03 R²).

Sample: 2 seasons

SupportedHeld outone VORP costs about $14.4M on today's marketM06

Do engine prices predict what teams actually pay in trades?

No: on 69 trades, rank correlation −0.05 with picks paid, below the declared bar of 0.30. Engine dollars are an internal yardstick, not a trade-price forecast.

Sample: 69 trades

Not supportedClean nullon 69 trades, rank correlation −0.05 with picks paid, below the declared bar of 0.30M07

How much did 2026 trades of past All-Stars pay over the engine's price?

Five trades paid −$2M to $182M over the engine price ($23M to $179M with veteran contracts at zero); median premium about $14.2M.

Sample: 2026 trades

SupportedIn sample onlyFive trades paid −$2M to $182M over the engine price ($23M to $179M with veteran contracts at zero)M11

What is a draft pick worth by slot?

A #1 pick is worth about 2.8 tenth picks in value over eight seasons, and the chance of an All-NBA player falls faster than value does. Draft-class bootstrap intervals on the tab.

SupportedIn sample onlyA #1 pick is worth about 2.8 tenth picks in value over eight seasons, and the chance of an All-NBA player falls faster than value doesM01

Why is #1 worth more than the curve says?

#1 is worth about 1.50× the average of picks 2 and 3 (1.07 to 2.02); the #1 was his class's best in 8 of 28 drafts, more than any other slot (no other slot more than 3). How big the premium looks depends on the yardstick. Updated 2026-10-15: the count was 10 of 28 before the 2026-10-02 full re-run (BPM fix and 82-game minutes basis), which made Paul George (#10) the best of 2010 over John Wall and Kawhi Leonard (#15) the best of 2011 over Kyrie Irving.

SupportedIn sample only#1 is worth about 1.50× the average of picks 2 and 3 (1.07 to 2.02)M02

What do protections and swap rights do to a pick's value?

Top-4 protection removes about 31% of a mid-table pick's value, because it removes the rare hit. A swap right is worth more three drafts out than one (it behaves like an option).

SupportedIn sample onlyTop-4 protection removes about 31% of a mid-table pick's value, because it removes the rare hitM04

Do pick prices follow the title odds a player adds (convex) or his production (linear)?

Production, at least as well: on 69 pick-for-player trades since 2019, mean miss 3.89 vs 4.46 (difference +0.57, −0.09 to +1.28: cannot separate); 0 of 66 variants favor title odds.

Not supportedClean nullon 69 pick-for-player trades since 2019, mean miss 3.89 vs 4.46 (difference +0.57, −0.09 to +1.28: cannot separate)M12

Does the market misprice player types?

The obvious pattern (scorers overpaid, role players underpaid) is mostly a measurement artifact. Under both directions of the regression, 1 of 15 types is mispriced: big interior finishers, overpaid by $1.1-6.4M a season.

Not supportedClean nullUnder both directions of the regression, 1 of 15 types is mispricedM18

Do buyers pay more at the trade deadline?

For time, not talent: per game delivered before the next offseason, deadline buyers pay 1.65× the offseason price in picks (1.33 to 2.08); per unit of recent form about the same, 1.11× (0.89 to 1.40).

SupportedIn sample onlyper game delivered before the next offseason, deadline buyers pay 1.65× the offseason price in picks (1.33 to 2.08)M13

Priced by what the buyer controls, is there a timing premium?

No consistent one: deadline buyers paid 1.41× (1.03 to 1.96) over 1999-2026, but only 0.88× (0.61 to 1.46) in 2019-26, and the trailing-form yardstick shows none.

Not supportedNot replicateddeadline buyers paid 1.41× (1.03 to 1.96)M15

Do buys made after the deadline cost more?

Withdrawn. All six such trades were June trades counted as if the season were nearly over; priced as offseason trades they cost no more (0.86×, 0.46 to 1.82).

Not supportedNot replicatedpriced as offseason trades they cost no more (0.86×, 0.46 to 1.82)M14

How long do bad teams stay bad (lottery recovery)?

A bottom-five team stays bottom-five the next season 47% of the time; three seasons later, about as often as a random team.

SupportedIn sample onlyA bottom-five team stays bottom-five the next season 47% of the timeM03

Once cap holds and extensions count, how many teams really have max room?

About 2.0 teams expected to fit a 25% max, not the 6.6 a maximum-room view shows.

Sample: 2.0 teams

SupportedIn sample onlyAbout 2.0 teams expected to fit a 25% max, not the 6.6 a maximum-room view showsM22

Which teams are squeezed by the tax and aprons?

For 2026-27, 12 teams are over the tax (5 by under $10M) and none over the second apron. In 2027-28 the Thunder are over the second apron on signed contracts with probability 0.74. 11 of 28 projected taxpayers ducked the tax at the last two deadlines (39%, 26 to 55).

Sample: 12 teams

SupportedIn sample only11 of 28 projected taxpayers ducked the tax at the last two deadlines (39%, 26 to 55)M16

Do teams trading up on draft night overpay?

They give 1.22× the curve value they receive (1.05 on the 29 trades with no future picks). The players they move up for do no better than their slot; the data cannot say whether the premium is earned back.

Sample: 29 trades

SupportedIn sample onlyThey give 1.22× the curve value they receive (1.05 on the 29 trades with no future picks)M25

Who signs a rookie-scale extension, and when?

Predictable from years 1-3: 2022 class out of sample AUC 0.87 (0.74 to 0.97), 10.8 predicted vs 9 signed. About 60% come in the October rush; 4.2 more 2023-class extensions expected before opening night (2 to 7).

SupportedHeld out2022 class out of sample AUC 0.87 (0.74 to 0.97)M17

Can contract decisions be predicted from production?

On later seasons: rookie extensions Brier 0.184 vs 0.196; restricted free agents staying 0.246 vs 0.287.

SupportedHeld outrookie extensions Brier 0.184 vs 0.196M23a

Can contract decisions be predicted from production?

No: Brier 0.269 vs 0.264 for the baseline.

Not supportedClean nullBrier 0.269 vs 0.264 for the baselineM23b

Does winning fill seats, and what would a rebuild cost the Bulls at the gate?

Ten more wins draw about 4.3% more fans a game that season (3.4 to 5.1) and 6.4% over three seasons, then the effect is gone. A two-season rebuild path goes with about 119,000 fewer Bulls tickets over five seasons (66,000 to 169,000).

SupportedIn sample onlyTen more wins draw about 4.3% more fans a game that season (3.4 to 5.1)O15

Do salaries discount players expected to miss games?

Cannot tell: one measure says yes (discount share −4.3, −9.0 to −0.5), the check measure cannot rule a full discount in or out (0.0, −1.6 to +1.2).

MixedClean nullone measure says yes (discount share −4.3, −9.0 to −0.5)M24

Are SLAP-lite players traded or paid differently?

At equal production and age they are traded less often (−0.088 log-odds per SD, −0.127 to −0.046, earlier run), weaker with role bands; the market pays them no premium.

SupportedIn sample onlyAt equal production and age they are traded less often (−0.088 log-odds per SD, −0.127 to −0.046, earlier run)M26

How often does a cheap contract hold a top-quarter player (climber type 10)?

15 of 497 low-contract players (3%; paid 3% of the cap or less, rookie-scale first-rounders excluded) had 2+ seasons in the top quarter of value, 1999-2025 (Parsons, Jokic, Whiteside). Descriptive.

Sample: 497 players

SupportedIn sample only15 of 493 low-contract players (3%)TB29

What are the Bulls' assets worth?

Wilson $56M, Giddey $47M, Buzelis $33M; Patrick Williams's contract is the largest liability (−$37M). Valued partly at his slot, Essengue ($23M at the deadline) stops counting as filler.

SupportedIn sample onlyWilson $56M, Giddey $47M, Buzelis $33MM08

What are the Bulls' own firsts worth?

Chicago's 2027-33 firsts are worth about 46 VORP together, or 2.5 average #1 picks. From four drafts out, a Bulls first is best priced as league average.

SupportedIn sample onlyChicago's 2027-33 firsts are worth about 46 VORP together, or 2.5 average #1 picksM05

How much cap room will the Bulls have in summer 2027?

Median maximum room $40M (10th-90th percentile $26-59M); a 46% chance of fitting a 25%-of-cap max contract. Simulation spread, not a confidence interval.

SupportedIn sample onlyMedian maximum room $40M (10th-90th percentile $26-59M)M20

Which summer-2027 plan gives the Bulls the most?

The three room plans end with 6.4-7.5 projected VORP kept and signed, against 4.8 staying over the cap, and leave $3-26M of 2028 room against $59M.

SupportedIn sample onlyThe three room plans end with 6.4-7.5 projected VORP kept and signed, against 4.8 staying over the cap, and leave $3-26M of 2028 room against $59MM21

Which players can the Bulls reach, and at what price?

Every target is priced with the cheapest legal Bulls package (checked with the CBA engine). Wembanyama tops the price list at $274M; the star tier holds 21 players at 3+ projected VORP.

Sample: 21 players

SupportedIn sample onlyWembanyama tops the price list at $274MM09

Which lead creators (the one piece type with support) are affordable?

26 of 27 lead creators under contract are reachable with picks and filler at the engine's price, but 16 of those are priced below zero. Cheapest above zero: Lillard $6.6M; with the median $14.2M star premium, Maxey $35.3M; 4 lead creators in the 2027 free-agent class fit the Bulls' room.

SupportedIn sample only26 of 27 lead creators under contract are reachable with picks and filler at the engine's price, but 16 of those are priced below zeroM10

Who runs the other 29 front offices, and how do they trade?

30 top executives, 1,912 trades since 1980-81; 9 are in the job under two years. Since Graham took over, the most active traders across from the Bulls are Winger, Peterson and Stevens.

Sample: 1,912 trades

SupportedIn sample only30 top executives, 1,912 trades since 1980-81O19

Has the salary premium for traditional centers, at equal prior-season VORP and age, risen from 2014-21 to 2021-26?

No: it fell. At equal past production and age, teams paid traditional centers +4.1% of the cap more than other veterans in 2008-13, +1.1% in 2014-21 and −1.4% in 2021-26 (change −2.6 points, −3.7 to −1.5).

Sample: 4,484 player-seasons, 17 seasons (2013-14 lacks payroll pages)

Not supportedIn sample only−2.6 points of the cap (recent minus mid) (−3.7 to −1.5 (90%, team-season bootstrap))CV02

Does P(plays in t+k) x an engine refit on players who play beat the asset engine, whose target already counts exits as zero?

No. On the engine's own validation split, the split changed three-season squared error by -1.1% (a tie); multiplying the current output by the chance he plays made it worse. The engine already counts seasons with no minutes as zero. Not switched.

Sample: 5688 test origins, 1468 players

Not supportedHeld outMSE engine minus split, VORP over t+1..t+3: -0.040 (-1.1% of the engine's); naive layer on today's output -0.068 (-1.9%) (-0.134 to +0.053; -0.153 to -0.000 (90%, 1,000 player bootstraps))SV09

Does a fitted minutes-fading draft prior beat the shipped asset engine (v1 projection + v2 slot blend) on three-season VORP?

A tie: +1.5% of the shipped engine's error (-1.0 to +4.3%). The fitted weight is flat and small (0.11 at 0 minutes, 0.06 at 1,000): log pick inside the engine already holds what slot knows. Production unchanged.

Sample: 5,688 test origins, 1,468 players

Not supportedClean nullError removed vs the shipped engine: R +1.5%; prior on top of v1 +0.7% (-1.0 to +4.3%; +0.0 to +1.5% (90%, 1,000 player bootstraps))DP02

Does asset_values_v2.py's slot blend beat the v1 projection on the players it applies to?

No. On the 827 held-out rows the rule applies to, dropping it removes 12.6% of the squared error (+5.1 to +21.7%). Low-minute young players fall short of their slot's average. Not changed here (not a declared candidate); Griffin's decision.

Sample: 827 test rows, 513 players

Not supportedHeld outError removed by dropping the blend (v1 alone vs shipped v2), blend rows: +12.6% (+5.1 to +21.7% (90%, 1,000 player bootstraps))DP05

In-game and strategy 17

Is clutch performance a trait?

Mostly no. A player's late-and-close edge carries into the next season at r 0.10 on court and 0.02 (−0.03 to +0.07) for players who change teams; his own shooting 0.07, and −0.003 under the top-10% leverage definition.

Not supportedClean nullA player's late-and-close edge carries into the next season at r 0.10 on court and 0.02 (−0.03 to +0.07)G03

Do players miss more free throws under pressure (the "unclenching" question)?

Yes: 1.8 fewer per 100 in the last two minutes of a close game than of a decided one, and 3.8 fewer when the throw can tie or take the lead in the last 30 seconds (1.7M throws, each player against himself).

SupportedIn sample only1.8 fewer per 100 in the last two minutes of a close game than of a decided one, and 3.8 fewer when the throw can tie or take the lead in the last 30 seconds ...G09

How much of a playoff game is three-point luck?

About 31% of what regular-season margins leave unexplained; the side with better three-point luck won 69% of games (e.g. the 2018 Rockets' Game 7).

SupportedIn sample onlyAbout 31% of what regular-season margins leave unexplainedB17

Can score, clock and possession give a calibrated win probability for every possession since 1996?

Yes: calibration slope 0.98 when each season is predicted from the others. Fit on 1996-2015 and tested on 2016-25, every model is too confident (0.88): leads are less safe since 2016.

SupportedHeld outcalibration slope 0.98 when each season is predicted from the othersG01

Who adds the most win probability, and does it repeat?

Gilgeous-Alexander led 2025-26. One season's total tracks the next (r 0.48 per possession); rank agreement with NBA.com's own leverage table 0.50.

SupportedHeld outGilgeous-Alexander led 2025-26G02

How much is transition worth?

17.2% of possessions, 0.16 points more per possession than the half court (2025-26). How often a team runs is stable (0.94); transition is 15.1% of the spread in team net ratings.

Sample: Team-seasons

SupportedIn sample only17.2% of possessions, 0.16 points more per possession than the half court (2025-26)G05

Is drawing fouls a skill?

As stable as free-throw shooting: year to year r 0.84 for free-throw rate and 0.86 for shooting fouls per shot, against 0.82 for FT%.

SupportedIn sample onlyyear to year r 0.84 for free-throw rate and 0.86 for shooting fouls per shot, against 0.82 for FT%G06

Do referee crews differ?

Yes: one crew calls about 1.2 more or fewer fouls per game than another (1 SD), and most of it carries over to the next season. Home-whistle differences (about 0.7 free throws a game) cannot be tested for persistence.

SupportedHeld outone crew calls about 1.2 more or fewer fouls per game than another (1 SD), and most of it carries over to the next seasonG08

Do stars get a reputation whistle after their first All-NBA team?

No clear effect: free-throw rate rises +0.010 per shot more than look-alikes' (−0.000 to +0.021); the shooting-foul rate does not move.

Not supportedClean nullfree-throw rate rises +0.010 per shot more than look-alikes' (−0.000 to +0.021)G07

When did this tactic change in our data, and does that match the told date (long-standing; pushed by analytics in the 2010s)?

Excess early first actions at 30-42 s before quarter ends rose from about 12% to 19% (2008-09) and fell to about 15% by 2025-26.

Sample: Play-by-play

SupportedIn sample only0.124 in 1996-97 to 0.147 in 2025-26; halfway 2004-05; exploratory break before 2008-09 (permutation p 0.001) (last season +0.137 to +0.157 (90%))ET09

When did this tactic change in our data, and does that match the told date (peak 2014-15 / 2015-16; rule change 2016-17 (last 2 minutes of every quarter))?

Early-in-possession fouls sending sub-55% shooters to the line peaked in 2014-15 and fell by about two-thirds after the rule (series added after the first run).

Sample: Play-by-play fouls

SupportedIn sample only-0.99 (2016-17..2018-19 minus 2013-14..2015-16) (-1.33 to -0.68 (90%))ET10

When did this tactic change in our data, and does that match the told date (rising through the 2010s; rule change 2022-23)?

Non-shooting fouls within 3 s of a live-ball start fell by about 40% in 2022-23.

Sample: Play-by-play

SupportedIn sample only-1.43 (2022-23..2024-25 minus 2019-20..2021-22) (-1.49 to -1.35 (90%))ET11

When did this tactic change in our data, and does that match the told date (conventional wisdom; analytics argued against it from about 2012)?

On-court share of the rest of the first half after a first-quarter second foul rose from about 20 points below normal to about 12.

Sample: Play-by-play and stints

SupportedIn sample only-0.202 in 1996-97 to -0.121 in 2025-26; halfway 2017-18; exploratory break before 2016-17 (permutation p 0.001) (last season -0.131 to -0.110 (90%))ET12

When did this tactic change in our data, and does that match the told date (2004-05 rule change)?

Not in this signature: guards' FT rate rose slightly but bigs' rose as much.

Sample: Player-seasons

Not supportedClean null-0.006 (2004-05..2007-08 minus 2000-01..2003-04) (-0.030 to +0.019 (90%))ET13

When did this tactic change in our data, and does that match the told date (2001-02 rule change (with defensive three seconds))?

Small: unassisted share +0.7 points, rim share flat; only four seasons before the rule.

Sample: Play-by-play shots

Not supportedClean null+0.007 (2001-02..2004-05 minus 1997-98..2000-01) (+0.004 to +0.010 (90%))ET14

The two-for-one fade since 2022-23 is a real change in end-of-quarter play?

Supported. Excess early first actions fell -2.6 points (-3.3 to -1.9) in 2022-23..2025-26 vs 2016-17..2021-22; teams acted early less often and the baseline did not move.

Sample: about 3,200-3,900 possessions a season (play-by-play)

SupportedIn sample onlyExcess 18.3% -> 15.7% (-2.6 points); observed share acting early -3.1; expected -0.4 (excess -3.3 to -1.9; observed -3.8 to -2.3; expected -0.9 to +0.0 (90%))ET-U3

Has the traditional center's share of on-court possessions and opening lineups risen from 2014-21 to 2021-26?

No. Traditional centers held +11.0% of on-court spots in 2014-21 and +7.0% in 2021-26 (−4.1 points, −5.1 to −3.0); flat since 2019-20.

Sample: 1,314,446 stint sides

Not supportedIn sample only−4.1 points of on-court spots (−5.1 to −3.0 (90%, team-season bootstrap))CV03

Game context and schedule 47

Do players shoot worse right after they check in, compared with their own later shots in the same kind of stint?

A player's first shot after he enters is worse than his later shots, by 1.9 points per 100 shots. The deficit fades over about three minutes.

Sample: Every regular-season FGA 1996-97..2025-26 (5,933,661 shots, 2,839 players). Expected make rate from a league shot model (distance, shot type, clock, score, period) plus court location plus the shooter's own skill by shot class. Player-season fixed effects; player-cluster bootstrap. Replicates in each era alone: 1997-2009 -1.88 (90% interval -2.31 to -1.43); 2010-19 -2.22 (90% interval -2.70 to -1.75); 2020-26 -1.22 (90% interval -1.78 to -0.70).

SupportedReplicated out of sampleFirst FGA after a mid-quarter entry vs his 3rd+ FGA (within 8 min of entry): -1.91 (90% interval -2.20 to -1.64) points per 100 shots vs expected; -0.84 (90% interval -0.96 to -0.72) FG percentage points. By minutes since entry, relative to 3-5 min: 0-1 min -3.00 (90% interval -3.38 to -2.62), 1-2 min -1.25 (90% interval -1.60 to -0.94), 2-3 min -0.81 (90% interval -1.15 to -0.46). (90% interval -2.20 to -1.64)CS01

How do usage and efficiency change with time into a player's shift?

In the first two minutes of a shift, players take fewer shots and make fewer than expected. Their team also scores less. This holds for starters and bench players, every type and every era.

Sample: Every player-minute 1996-97..2025-26, cut into lineup-stint rows; within-player-season deviations; player bootstrap.

SupportedReplicated out of sampleShot-making vs his own season, minutes 0-2 of a shift: starters -2.93 (90% interval -3.14 to -2.71), bench -3.72 (90% interval -3.95 to -3.47) points per 100 FGA. FGA per 100 possessions: starters -1.12 (90% interval -1.18 to -1.06), bench -1.96 (90% interval -2.01 to -1.90). (90% interval -3.14 to -2.71)IG02

Is there a cold start in free throws, where shot selection cannot explain it?

With shot selection removed, the first free-throw trip after a player enters is about 2 percentage points worse. The longer he sat, the bigger the drop.

Sample: Every regular free throw 1996-97..2025-26 (technical, flagrant, take and clear-path FTs excluded), controls for position in the trip (1 of 2, 2 of 2 and so on), clutch and period. Eras alone: 1997-2009 -1.78 (90% interval -2.09 to -1.52); 2010-19 -2.01 (90% interval -2.33 to -1.71); 2020-26 -2.39 (90% interval -2.76 to -1.98).

SupportedReplicated out of sampleFirst regular FT trip of a mid-quarter stint vs later trips: -2.00 (90% interval -2.19 to -1.81) percentage points (player-season FE); player-game FE -1.62 (90% interval -1.83 to -1.41). Rest before entry 12+ min minus under 4 min: -1.19 (90% interval -1.57 to -0.78). (90% interval -2.19 to -1.81)CS04

Is the cold start caused by the dead-ball restart (a called play, a set defence) or by sitting on the bench?

The first shot after a timeout, by a player who stayed on the floor, is as good as his later shots. Bench time is what makes the first shot worse; a dead-ball restart alone does not.

Sample: Timeout restarts identified from possessions with a timeout before the first attempt (the timeout clock itself is not in every feed).

SupportedIn sample onlyFirst FGA after a timeout restart, players on court 3+ min: -0.15 (90% interval -0.53 to +0.22) points per 100 shots. (90% interval -0.53 to +0.22)CS05

Is the cold start specific to checking in mid-quarter, or does it follow any entry off the bench?

Bench players who enter at the start of a quarter start just as cold. Starters opening the second half do not start cold.

Sample: Same data and model as cold-start-1. Quarter-break entry = a player who sat at the end of one quarter and opened the next.

Not supportedClean nullFirst-FGA effect after a quarter-break entry -2.20 (90% interval -2.91 to -1.40); difference mid minus quarter-break +0.29 (90% interval -0.54 to +1.06). Game start -1.44 (90% interval -1.90 to -0.98); half start -0.04 (90% interval -0.51 to +0.37). (90% interval -2.91 to -1.40)CS03

Griffin's idea: shooters may start cold while post players score best from the post right after checking in. Does the data agree?

Spacers and post players show the same first-shot deficit. Post players' post-ups and rim shots right after entry are also below expected.

Sample: Player types per player-season (200+ FGA): post (top 15% in hook / short turnaround share), creator, spacer (top quarter in 3PA share), big (6-10+), other. Post-ups are a shot-label proxy, not play-type data.

Not supportedClean nullSpacer minus post first-FGA effect: -0.32 (90% interval -1.34 to +0.74). Post players' post-up and rim shots: -1.62 (90% interval -2.51 to -0.83). Spacers' threes: -2.63 (90% interval -3.81 to -1.39). (90% interval -1.34 to +0.74)CS07

How does shot-making vary with shot number in the game?

Descriptive: a player's first shot of the game is 1.23 points per 100 shots below his average (-1.44 to -1.02); shots 4-6 are +0.31. Players who start hot get more shots, so this table leans against flow.

Sample: 5.9M shots

SupportedIn sample onlyFirst shot of the game: -1.23 per 100 shots (-1.44 to -1.02)UE12

Griffin's hypothesis: catch-and-shoot role players start cold on threes at their first first-half entry, but not in the second half once they have played.

Low-usage shooters' first three after their first entry is well below expected. Their first three after re-entering in the second half is less cold, but the gap is not clear.

Sample: Catch-and-shoot role players = 1,790 player-seasons with usage below the median and 3PA share in the top third (examples: Joe Johnson 2004, Dorell Wright 2010, Quentin Richardson 2004, Peja Stojakovic 2007). Non-self-created threes; non-starter stints.

MixedIn sample onlyFirst three, first entry of the game in the first half: -4.36 (90% interval -6.27 to -2.50) points per 100 threes; first entry of the second half after playing in the first: -3.02 (90% interval -5.10 to -1.02); difference -1.34 (90% interval -3.97 to +1.33). (90% interval -6.27 to -2.50)IG01

Does shot-making fall with minutes into a stint (fatigue)?

Starter-level players shoot 2.34 points per 100 shots worse at 9+ minutes into a stint than at 3-6 minutes (-2.65 to -2.01). Bench players look better the longer they stay, but that is mostly coaches keeping hot players on.

Sample: 5.9M shots

SupportedIn sample onlyStarters, 9+ minus 3-6 minutes into the spell: -2.34 per 100 shots (-2.65 to -2.01)UE11

What do back-to-backs, travel and altitude cost?

A back-to-back costs 1.8 points of margin on the road and 1.5 at home; the cost has not shrunk over time.

SupportedIn sample onlyA back-to-back costs 1.8 points of margin on the road and 1.5 at homeG10a

How do players who play the second night of a back-to-back perform?

0.3 TS points worse and 0.17 game score per 36 lower; the drop does not grow with age, and those who play get slightly more minutes.

SupportedIn sample only0.3 TS points worse and 0.17 game score per 36 lowerG11

Beyond back-to-backs and three-in-four, does a crowded week cost?

Yes, but smaller than a back-to-back. Each extra game in the previous 7 days costs -0.34 (-0.50 to -0.21) points of margin, about a fifth of a back-to-back (-1.67), on top of the back-to-back, rest and three-in-four terms. It runs through defense (+0.40 (+0.24 to +0.52) points per 100 allowed). Four games in five nights: -0.39 (-0.82 to +0.07).

Sample: 68,414 team-games (34,207 games); ratings from games before each game

SupportedHeld outmargin per extra game in the previous 7 days: -0.340 (-0.501 to -0.213 (90%))GC12

Does regular-season rest pay off in the playoffs?

No design shows a payoff: playoff TS per 3 fewer minutes a game +0.04 (−0.11 to +0.22; effects under about 0.26 could not show). The one estimate clear of zero runs through injury: 10 points more games missed goes with 5.7 points less playoff availability.

Not supportedClean nullplayoff TS per 3 fewer minutes a game +0.04 (−0.11 to +0.22; effects under about 0.26 could not show)T20

Do teams score or defend worse when the game runs faster or slower than they are used to?

Not detectable. Per 3 possessions per 48 of mismatch (either direction), a team's own offense changes by +0.05 (-0.09 to +0.18) points per 100 against its pre-game expectation; both offenses together change by +0.11 (-0.18 to +0.37). Held-out years agree (+0.07 (-0.13 to +0.30)) and the next-opponent placebo is +0.11 (-0.02 to +0.22).

Sample: 68,414 team-games (34,207 games); ratings from games before each game

Not supportedClean nullown offense per 100, per 3 poss/48 of mismatch: +0.053 (-0.086 to +0.179 (90%))GC02

Does a team's result against its pre-game rating expectation change with the game's pace?

No. Against the pre-game gap the margin residual moves +0.18 (-0.04 to +0.45) points per 3 possessions per 48 (curvature -0.10 (-0.25 to +0.02)). By actual pace minus the team's norm, the average margin residual stays within about 0.1 points in every bin except the slowest (more than 6 below the norm: +0.32 (+0.07 to +0.55)).

Sample: 68,414 team-games (34,207 games); ratings from games before each game

Not supportedClean nullmargin residual per 3 poss/48 of gap: +0.185 (-0.043 to +0.448 (90%))GC03

Do half-court teams lose more than transition teams when the opponent plays faster?

The declared test is null: +0.10 (-0.11 to +0.34) points of margin per 3 possessions per 48 (half-court minus transition), but its placebos were not centred on zero. With own-pace controls (added afterwards) the contrast is -0.24 (-0.53 to +0.02), in the hypothesised direction but including zero; it is -0.57 (-1.01 to -0.18) in 2015-2025 and -0.13 (-0.45 to +0.18) in 1997-2014.

Sample: 68,414 team-games (34,207 games); ratings from games before each game

Not supportedNot replicatedhalf-court minus transition, margin per 3 poss/48 (revised spec): -0.238 (-0.530 to +0.021 (90%))GC04

Do teams built on defense hold up better than others when the opponent plays faster?

A small lead. Defense-first teams beat their rating expectation by +0.31 (+0.11 to +0.55) points of margin more than other teams per 3 possessions per 48 that the opponent is faster. The next-opponent placebo is -0.03 (-0.30 to +0.29); the held-out years give +0.43 (+0.05 to +0.87) and the early years +0.24 (-0.01 to +0.47).

Sample: 68,414 team-games (34,207 games); ratings from games before each game

MixedHeld outdefense-first minus others, margin per 3 poss/48 (revised spec): +0.310 (+0.107 to +0.549 (90%))GC05

What is playoff home court worth beyond the skill difference between the teams?

Within-series estimate 4.09 points (90% 3.61 to 4.57), 1996-2026; regular season 2.77 (2.56 to 2.96) by the same method; difference 1.32 (0.82 to 1.84).

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

SupportedIn sample only4.09 points per game beyond skill; 1.32 more than the regular season (ratio 1.48) (3.61 to 4.57; difference 0.82 to 1.84; ratio 1.29 to 1.69)G12

Does the playoff home edge survive without fans and travel?

Supported by the 2020 bubble: same nominal hosts and 2-2-1-1-1 order, no fans or travel, home edge -0.07 (-2.58 to 2.45), 4.5 below nearby postseasons.

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

SupportedIn sample onlybubble minus nearby postseasons -4.48 points (-7.08 to -1.78)PH06

Does home court change the chance of winning the series, beyond skill?

Supported (model-implied): hosting is worth 6.6 percentage points against the opponent hosting (5.8 to 7.4), 8.0 for even teams. The direct series test (70 underdog-hosted series) gives 14.6 (5.5 to 23.6), consistent but noisy. Updated 2026-10-15: the model-implied value was 5.8 (5.1 to 6.5) before the 2026-10-09 fix that moved the mixed-model fit to its true optimum (series-skill spread omega 4.37 -> 1.70; agents/statsmodels-port/verify.json); a wider skill spread had been absorbing part of home court. The direct test did not move.

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

SupportedIn sample only6.6 percentage points of series-win probability (vs opponent hosting); 3.0 vs neutral (5.8 to 7.4; direct test 5.5 to 23.6)PH07

What does one extra point of regular-season margin buy in seeding, home court, playoff games and title odds, by team?

Supported in simulation: one point of margin per game adds 0.25 home playoff games for the average team (0.31 hosted as series host) and 5.2 points of round-1 hosting odds; 0.42 home games for teams ranked 4th-8th; near zero for lottery teams and top seeds.

Sample: 10,000 simulated seasons per team and margin step

SupportedIn sample only+0.25 home playoff games, +0.31 as series host, +5.2 pts P(host round 1), +0.16 pts title odds per point (league average); 2.54 wins per point (real slope) (slope 90% 2.45 to 2.63; home games 0.24 to 0.25 with the playoff home edge at G12's 90% ends; Monte Carlo SE 0.01-0.03)CC03

How often were seeds, and series hosts, within one or two wins?

Mixed: adjacent seeds are often close (4th and 5th within 2 wins in 57% of conference-seasons; 6th and 7th within 1 win in 65%), but the host of a real best-of-7 series led its opponent by 2 wins or fewer in only 19% (median edge 7 wins).

Sample: 40 conference-seasons; 330 series

MixedIn sample only4/5 gap <= 1 win 48%, <= 2 57%; series host edge <= 2 wins 19%CC04

Does the playoff home edge change in games 5, 6 and 7, once the selection of series that reach them is removed?

Yes: games 5-7 pooled carry 3.6 points beyond skill after correcting for which series reach them, -0.5 (-1.6 to 0.6) against games 1-4; the within-series design gives -0.5.

Sample: 387 series, 2160 games; secondary 1983-2026 sample 478 series, 2680 games

SupportedIn sample onlygames 5-7 minus games 1-4: -0.52 (prior skill), -0.48 (within series); corrected edge 3.58 / 3.62 (-1.58 to 0.55; -1.56 to 0.58)PH10

Does the playoff home edge follow the regular season's decline since about 2010?

Not supported: since 1983 the regular-season edge fell 0.72 points per decade, the playoff edge 0.22 (interval includes no decline); trends differ by 0.50 per decade.

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

Not supportedIn sample onlyplayoff trend -0.22 per decade vs regular season -0.72; difference +0.50 (playoff -0.49 to 0.10; regular season -0.85 to -0.59; difference 0.17 to 0.87)PH02

How much of the raw playoff home margin is skill rather than venue?

No: skill explains 4.1% of the raw home margin (-2.0 to 10.7%); the lower seed hosts games 3, 4 and 6, so home teams are only slightly better on average.

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

Not supportedIn sample onlyRaw 4.27 vs within-series 4.09; every skill control (margin gap, SRS, SRS + game-1 roster xRAPM) gives 3.96 to 3.97 (skill share -2.0% to 10.7%)PH01

Does the playoff home edge differ by round?

Not supported: conference finals and Finals minus rounds 1-2 = +0.39 points (-0.61 to 1.39).

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

Not supportedClean nulllate minus early rounds +0.39 points (-0.61 to 1.39)PH03

Is the home edge larger in game 7s and other deciding games?

Not distinguishable: the deciding-game term is -0.08 (-1.83 to 1.66), selection-bias corrected. Updated 2026-10-09 after the mixed-model fit was moved to its true optimum (it was +0.71 before). Hosts won 77 of 107 game 7s, about what home court plus skill predicts.

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

Not supportedClean nullextra host margin in deciding games -0.08 points (-1.83 to 1.66)PH04

Does the side facing elimination outperform its series level?

Not supported, and the sign runs the other way: the side facing elimination plays about 1 point below its level (-0.97, 90% -1.81 to -0.12, selection-bias corrected). Corrected 2026-10-09: the earlier +0.08 (-0.79 to 0.95) came from a mixed-model fit that had stopped before its optimum (REML log-likelihood 16.4 lower). The numpy port (agents/statsmodels-port/verify.json) finds the true optimum (omega 4.37 -> 1.70). The fixed-effects version, corrected, agrees in sign (-1.37). One test among several in this family, so treat it as small and borderline.

Sample: 435 series, 1692 always-played games; 34,487 regular-season games

Not supportedIn sample only-0.97 points per game (the side facing elimination plays slightly below its level) (-1.81 to -0.12)PH05

Is the home edge in game 6 different from games 1-4?

Unsettled: game 6 sits about 2 points below games 1-4 (-1.8 prior skill, -2.1 within series); only the within-series interval excludes zero, and 1983-2026 data give -0.8.

Sample: 387 series, 2160 games; secondary 1983-2026 sample 478 series, 2680 games

MixedIn sample onlygame 6 minus games 1-4: -1.78 (prior skill), -2.15 (within series) (-3.71 to 0.10; -3.93 to -0.37)PH11

Does the home edge change with the series score, in particular for a home team facing elimination?

Suggestive: the home team's edge in this state is about zero (0.6 / -0.3 points), -3.5 and -4.4 against the constant edge; fails the multiple-comparison bar for 15 states.

Sample: 387 series, 2160 games; secondary 1983-2026 sample 478 series, 2680 games

MixedIn sample onlyhome edge beyond constant, host up 3-2 in game 6: -3.54 (prior skill), -4.39 (within series) (-6.07 to -1.07; -6.81 to -2.05; Bonferroni -7.87 to 0.72 / -8.42 to -0.51)PH12

Does the result of game 1 change the host's game-2 margin beyond what skill predicts?

Suggestive: after a game-1 loss the host's game-2 margin beats the constant-skill model by +3.2 points (1.1 to 5.2); after a game-1 win it trails by -1.0. Both games are at the host, so venue cannot explain it.

Sample: 387 series, 2160 games; secondary 1983-2026 sample 478 series, 2680 games

MixedIn sample onlyhost 0-1 entering game 2: +3.21; host 1-0: -1.04 (1.10 to 5.25; -2.31 to 0.18; 0-1 Bonferroni -0.10 to 6.67)PH13

Does running a play for the new player right away help or hurt?

First shots taken in the team's first possession after a player enters are much worse than first shots that come later.

Sample: Mid-quarter entries. Shot model already adjusts for shot type, distance, location and shot clock.

SupportedIn sample onlyFirst FGA in the first possession after entry -3.86 (90% interval -4.37 to -3.42); in a later possession -1.50 (90% interval -1.78 to -1.22); difference -2.36 (90% interval -2.86 to -1.90). (90% interval -4.37 to -3.42)CS08

Do some players reliably start colder than others?

Players who start cold in even seasons are no more likely to start cold in odd seasons. Individual cold-start numbers are noise.

Sample: Players with 100+ mid-entry first FGAs in each half. Shrunk table covers 1352 players.

Not supportedClean nullSplit-half correlation of player first-shot effects (even vs odd seasons, 1226 players): +0.012; Spearman-Brown reliability +0.023.CS06

Who controls pace when two teams with different norms meet?

No one gets extra say. A game's pace is the league average plus each team's own pace deviation. The share of control is +0.49 (+0.48 to +0.50) for the faster team, +0.50 (+0.49 to +0.51) for the home team and +0.51 (+0.50 to +0.51) for the better team (0.5 = equal say).

Sample: 68,414 team-games (34,207 games); ratings from games before each game

Not supportedClean nullfaster team's share of control: +0.493 (+0.483 to +0.503 (90%))GC01

How do playoff games differ from the regular season?

Slower (−2.1 possessions per 48), lower-scoring (−3.5 per 100 raw; −1.3 beyond the better opponents) and more concentrated on the top two players (usage share 41% → 44%).

SupportedIn sample onlySlower (−2.1 possessions per 48), lower-scoring (−3.5 per 100 rawB14

Do bigs or guards change most, against their own baseline, when the opponent plays faster?

Yes, slightly. Per 3 possessions per 48 of opponent pace, bigs (82 in and up) gain +0.26 (+0.17 to +0.35) points per 100 possessions and +0.38 (+0.24 to +0.53) TS percentage points relative to guards (75 in and under). Guards' own TS slope is -0.12 (-0.22 to -0.03); bigs' is +0.26 (+0.16 to +0.37).

Sample: 603,408 player-games, 2,591 players

SupportedHeld outbig minus guard, points per 100 possessions per 3 poss/48: +0.261 (+0.169 to +0.346 (90%))GC08

Do young or athletic players gain in fast games relative to their own baseline?

No. Every group gains a little when the opponent plays faster, by about the same amount. Young (23 and under) minus 30-and-over: +0.04 (-0.05 to +0.13) game score per 100 possessions per 3 possessions per 48. Athletic (top third of 2015-16 fast-break speed for height) minus others: +0.11 (-0.04 to +0.25).

Sample: 603,408 player-games, 2,591 players

Not supportedClean nullyoung minus 30+, game score per 100: +0.040 (-0.053 to +0.134 (90%))GC07

Do high-usage creators gain or lose in fast games relative to their own baseline?

Unclear. Creators' TS changes like everyone else's (contrast +0.00 (-0.11 to +0.11) percentage points). Their points per 100 contrast is -0.07 (-0.14 to -0.01), but it flips sign between 1997-2014 (-0.20 (-0.26 to -0.12)) and 2015-2025 (+0.20 (+0.11 to +0.34)), and its placebo is not null (+0.07 (+0.01 to +0.13)).

Sample: 603,408 player-games, 2,591 players

MixedNot replicatedcreator minus others, TS percentage points: +0.000 (-0.110 to +0.110 (90%))GC09

What do back-to-backs, travel and altitude cost?

Denver and Utah have the largest home edges, about 2.0 points beyond the league's.

SupportedIn sample onlyDenver and Utah have the largest home edges, about 2.0 points beyond the league'sG10b

Do visitors fade late in games at Denver and Utah?

Only on the second night of a back-to-back. Visitors' fourth quarter minus their first three, in net points per 100 possessions, is -1.4 (-3.3 to +0.2) at altitude beyond other arenas (includes zero). On a back-to-back it drops a further -2.6 (-4.4 to -0.6). The Q2 placebo is +0.8 (-1.4 to +2.9).

Sample: 34,207 visitor games, 2,302 at Denver/Utah

MixedHeld outextra Q4 drop, visitor at altitude on a back-to-back, per 100: -2.636 (-4.416 to -0.643 (90%))GC10

Does a player's usage change with the quality of the opposing unit?

When 0-1 opposing starters are on the floor, a player's usage share rises about one point above his own norm.

Sample: Opposing starters = players on court at the opening tip of that game.

SupportedIn sample onlyUsage share vs his own season: 0-1 opposing starters +0.94 (90% interval +0.89 to +0.99); 4-5 opposing starters -0.51 (90% interval -0.55 to -0.48) points. (90% interval +0.89 to +0.99)IG03

How does foul trouble change a player's game?

In foul trouble, players shoot less often and foul less, with no change in shot-making.

Sample: Foul trouble at the start of a lineup stint: 2+ fouls in Q1, 3+ in Q2, 4+ in Q3, 5+ in Q4/OT.

SupportedIn sample onlyVs his own season, in foul trouble: FGA per 100 possessions -1.65 (90% interval -1.81 to -1.51); fouls per 36 -0.85 (90% interval -0.91 to -0.78); shot-making -0.30 (90% interval -1.09 to +0.64). (90% interval -1.81 to -1.51)IG04

Is there a fatigue interaction between pace and back-to-backs or fourth quarters?

No. Being forced faster on the second night of a back-to-back changes the margin residual by -0.04 (-0.26 to +0.14) per 3 possessions per 48. In fourth quarters, a faster predicted game changes a team's own offense (Q4 minus Q1-Q3) by -0.17 (-0.37 to +0.04) per 100; the back-to-back interaction is +0.35 (+0.08 to +0.63), the opposite sign to fatigue.

Sample: 68,414 team-games (34,207 games); ratings from games before each game

Not supportedClean nullmargin, forced faster x back-to-back: -0.040 (-0.256 to +0.141 (90%))GC06

How do teams do in the first home game after a long road trip, and late in long trips?

No letdown. The first home game after a 4+ game trip: -0.14 (-0.55 to +0.38) points against the pre-game expectation; after a 6+ trip -0.42 (-1.24 to +0.28). The last game of a 4+ trip: -0.39 (-0.99 to +0.17). Games 5+ of a trip: +0.62 (+0.18 to +1.14), but not in the held-out years (+0.12 (-0.58 to +0.85)).

Sample: 68,414 team-games (34,207 games); ratings from games before each game

Not supportedClean nullhomecoming after a 4+ game trip, margin: -0.143 (-0.554 to +0.377 (90%))GC11

When did this tactic change in our data, and does that match the told date (late 2000s on; told partial reversal in the 2020s)?

League offensive rebound rate fell from about 33% to 22% (low 2019-20) and is back near 26%.

Sample: Team box scores

SupportedIn sample only0.325 in 1985-86 to 0.260 in 2025-26; low point 2019-20; exploratory break before 2005-06 (permutation p 0.001) (last season +0.252 to +0.269 (90%))ET05

How do usage, shot mix and efficiency differ by when and how a player enters (starter vs bench, first vs re-entry, each half)?

Against their own norms, starters re-entering in the second half draw more free throws and run less in transition. Bench players' first stints are below their norm in shot-making.

Sample: Contexts S1-S4 (starters) and N1-N5 (bench) defined in agents/cold-start/plan.md.

SupportedReplicated out of sampleVs his own season: FTA per 100 possessions S4 second-half re-entry +1.93 (90% interval +1.84 to +2.00); transition share S4 -3.60 (90% interval -3.72 to -3.47); shot-making N1 first bench entry -0.37 (90% interval -0.53 to -0.18), S3 half start +0.50 (90% interval +0.35 to +0.65). (90% interval +1.84 to +2.00)IG05

The back-to-back cost grew because teams rest stars on the second night?

Only a small part. The second-night cost grew -0.92 points (-1.47 to -0.22) from 1997-2021 to 2021-26; the part running through top-two absences grew -0.11 (-0.21 to -0.01), about 12% of it.

Sample: 34269 games

MixedIn sample onlyGrowth of the second-night cost -0.92: through who plays -0.11 (12% of the growth, 1% to 35%); with the same top two available -0.81 (who plays -0.21 to -0.01; same top two -1.36 to -0.16 (90%))ET-U1

Data quality and methods 8

How well is each input measured?

Counting stats are reliable at 500+ minutes (0.85 to 0.98). The noisy inputs are true shooting (0.70) and 3P% (half weight needs about 193 attempts); steals for size need about 316 minutes.

SupportedIn sample onlyCounting stats are reliable at 500+ minutes (0.85 to 0.98)E15

How wrong are listed heights?

The database stores one final height per player. Listings run +1.24 in over barefoot for players retired before 2019-20 and +0.61 in after.

SupportedIn sample onlyListings run +1.24 in over barefoot for players retired before 2019-20 and +0.61 in afterE16

Can a box-score stand-in measure athleticism?

No: the stand-in tracks 2015-16 in-game peak speed at rank correlation 0.09. Athleticism is unmeasurable from box scores before the combine era.

Not supportedClean nullthe stand-in tracks 2015-16 in-game peak speed at rank correlation 0.09E25

How much does survivorship distort aging curves?

Without a survivor correction, the 31-35 drop in 3P% is -0.47 league spreads; with it, -0.18. Shooters who keep playing are partly the lucky ones, and their next season regresses.

Sample: Player-season pairs, 200 player resamples

SupportedIn sample only3P% decline 31-35: -0.47 uncorrected vs -0.18 corrected (spreads) (-0.34 to -0.03 (corrected))TA08

Do shrinkage strengths fitted by prediction (empirical Bayes) beat hand-set ones?

Mostly close. Catch-and-shoot shrinkage was far too weak (k 49 → 215) and play-type efficiency badly under-shrunk (25 → 125-370).

SupportedHeld outCatch-and-shoot shrinkage was far too weak (k 49 → 215) and play-type efficiency badly under-shrunk (25 → 125-370)E12

Does weighting each pair by next season's minutes bias the survivor age curve?

Yes. The front-page delta weights each pair by the harmonic mean of both seasons' minutes; next season's minutes are an outcome. With equal weights the survivor curve peaks at 26 (26 to 28) and sits 0.18 spreads (0.14 to 0.23) lower at 28.

Sample: 10,827 at-risk pairs, 200 player bootstraps

SupportedIn sample onlyFront-page curve minus equal-weight survivor curve at 28: 0.18 spreads; at 33: 0.19 (0.14 to 0.23; 0.13 to 0.26 (90%))SV02

How do ABA values translate to the NBA scale?

ABA-to-NBA movers kept 0.76 of their ABA value spread (90% [0.608, 0.945]) with a level shift of -0.64 per 100 (90% [-1.04, -0.232]).

Sample: 104 ABA->NBA pairs, 1788 NBA pairs

SupportedIn sample onlyscale 0.76, shift -0.64 (scale [0.608, 0.945], shift [-1.04, -0.232])AG12

How strong was each era's league in absolute terms?

Untested: values here are relative to each season's league; an era-bridging model (players' value changes across league changes, with an age curve) could estimate absolute league strength.

Not supportedIn sample onlyAG15