Running The Bulls, Ahead of the Herd

The NBA is driven by stars. How do the Chicago Bulls find the next star and put the best supporting cast around him?

Winning in the NBA is a constant battle to scrap for every edge you can possibly find. This is traditionally thought of as the domain of analytics, which is often seen as being in tension with the eye test. In fact, analytics and the eye test are complementary.

An NBA analytics department must have an impact model that blends lineup ratings and box-score data. My model is on par with the leading public models.

SiPM, my model, forecasts as accurately as DARKO and EPM
−0.200.20.4← other model betterSiPM better →vs DARKO0.45 vs 0.30vs EPM0.50 vs 0.44SiPM minus the other model

Both intervals cross zero: the models are level.

The higher SiPM rates a lineup, the better it plays
12345678910−6−30369SiPM forecast, tenths (1 = lowest)actual net rating per 100

14,274 lineups from seasons the model never saw.

The question is what you do from there. I want to model trajectories and test questions. Everything works backwards from the end goal: winning NBA championships.

Overall impact (band: 90% interval)Explosive traits, averageSkill traits, average
today's 20- to 23-year-olds, 2030-31 to 2033-34212427303336−1−0.500.51agechange since age 21, league spreads

Shaded: the ages today's 20- to 23-year-olds reach in 2030-34.

Offensive breakoutsDefensive breakouts
≤202122232425262728293031+0246810age in the breakout seasonbreakouts per 100 player-seasons

The NBA has singular star talents. Looking at the best players today, each has a unique game:

Wemby Jokic SGA Giannis Kawhi LeBron Steph KD Luka Ant

The name came from my hypothesis that was found to be unproven: that identifying the next singular star could be done by data alone. Data narrows the list, shows whose game is still growing, and finds who fits around him. Singularity is identified by watching the game.

820questions tested, by topic
Aging and trajectories219Player ratings152Stars, titles and fit88Scoring and creation80Defense73Game context and strategy66Health and availability55Data quality51Contracts and markets36

1Trajectories: how each part of a player's game grows and fades

A rebuilding team invests in primes. This figure shows which traits a roster gains and loses as its players age.

Figure 1

Most explosive box-score traits peak at 21 or younger and fade first; passing peaks at 26 and ball security at 25, while three-point and mid-range shooting hold into the 30s

GuardsWingsBigs
Rim share of shotsexplosive21252933−1.5−1−0.500.51
Dunks per 36explosive21252933−1.5−1−0.500.51
Transition shareexplosive21252933−1.5−1−0.500.51
Free-throw rateexplosive21252933−1.5−1−0.500.51
Blocks per 36explosive21252933−1.5−1−0.500.51
Off. rebounds per 36explosive21252933−1.5−1−0.500.51
Three-point %skill21252933−1.5−1−0.500.51
Free-throw %skill21252933−1.5−1−0.500.51
Mid-range %skill21252933−1.5−1−0.500.51
Assists per 36skill21252933−1.5−1−0.500.51
Ball securityskill21252933−1.5−1−0.500.51
Steals per 36defense21252933−1.5−1−0.500.51
Def. rebounds per 36defense21252933−1.5−1−0.500.51
Box-score defensedefense21252933−1.5−1−0.500.51
True shootingoverall21252933−1.5−1−0.500.51
Overall impactoverall21252933−1.5−1−0.500.51
A roster's explosive strengths are the first to go. Rim shots, dunks, transition shots, blocks and offensive rebounds peak at 21 or younger and slide from there; passing peaks at 26, free-throw shooting at 28 and ball security at 25; three-point and mid-range shooting hold into the 30s; overall impact peaks at 26 and holds to 28 before it falls. Guards age best: their overall impact peaks at 28, against 26 for wings and bigs, while bigs lose shooting efficiency and ball security first.

Line: typical change since age 21, in league spreads (up = better, so ball security is turnovers turned upside down). Dot: peak age. Each player's change from one season to the next counts once; players likely to leave the league are weighted up, using only what was known that season. A line stops once fewer than 30 player-seasons of that position remain, which is why bigs' three-point line ends early. Late-career ages carry the widest uncertainty. Box-score defense is the weakest measure here: age is one of its model's inputs, so its curve partly echoes that age term.

2Findings

Basketball minds are constantly asking how to play the game better. Those questions are testable, and testing them shows how well the eye test and analytics go together.

Findings at a glance

  • Trajectories. Explosive box-score traits peak at 21 or younger and fade first. Passing peaks at 26 and ball security peaks at 25. Three-point and mid-range shooting hold into the 30s. Guards age best; bigs lose shooting efficiency and ball security first. Defensive breakouts come about two years after offensive ones.
  • Usage and efficiency. When a teammate's absence hands a player a bigger role, his true shooting falls about 0.5 points per usage point. The drop comes mostly from losing the teammate who set him up, not from the extra shots.
  • Fit. Spacers and interior bigs add value next to a star creator. Two star creators together are worth about 0.9 per 100 less than their ratings add up to.
  • Threes versus twos. In the half court, threes and twos are now worth the same once offensive rebounds and the opponent's next trip are counted: NBA teams have found the balance. Shots at the rim beat a three. Midrange twos do not. What I want to track is how the balance between threes and twos shifts, so the Bulls can lead the pack on the next play-style revolution.
  • What data cannot see. On defense, award votes add signal the numbers miss. A model built on public data captures about half of the signal in a player's next three seasons.
  • Coaching decisions. Leaving a starter in after an early second foul is worth about a third of a point of win probability. Coaches give up about 0.3 wins a season, mostly by sitting starters in foul trouble.
  • Strategy. Crashing the offensive glass costs almost nothing in transition. An isolation-heavy offense shows no measurable playoff penalty, and playing faster with the ball does not buy offense.
  • How it was tested. 820 questions tested as statistical hypotheses.
Figure 2

I thought to test it: fifteen common beliefs, measured

Many basketball truisms hold up; what's notable is their size. A coaching staff can prepare with those sizes.

Dot: estimate. Bar: 90% interval (95% for playing hurt). No bar: the test reported a single estimate or a spread.

Playoff home court
Worth about 4 points a game beyond skill, 1.5 times the regular season's; it vanished in the 2020 bubble.
−2024points per game beyond skillPlayoffs+4.09 (+3.61 to +4.57)Regular season+2.77 (+2.56 to +2.96)2020 bubble, no fans−0.07 (−2.58 to +2.45)
Free throws under pressure
Players make fewer free throws when the game is on the line.
−4−20free throws made per 100Last 2 min, close vs decided−1.8 (−2.2 to −1.3)Last 30 s, can tie or lead−3.8 (−5.0 to −2.7)
The hot hand
Real but small once shot difficulty is priced: hot players take harder shots.
−0.200.20.40.6percentage points of make rate, shot pricedAfter one make−0.01 (−0.07 to +0.05)After three makes in a row+0.41 (+0.29 to +0.53)
Luck in playoff surprises
Three-point luck explains about a third of what regular-season margins miss, though a real playoff shooting skill would count as luck here.
Share of unexplained playoff margin31%Games won by the luckier side69%
Referees
Referees differ in how many fouls they call, and consistently so. A crew of three differs by about 1.2 fouls a game (one SD). Each referee's effect is shrunk toward average by how noisy it is.
If referees did not differ at all (chance only)A normal curve with the referees’ actual spread147272714141−2−101fouls per game vs average (95 referees, 50+ games)
Playoffs widen quality gaps
Between playoff teams, a point of net-rating gap buys 1.19 points of playoff margin against 0.75 in the regular season.
00.250.50.75extra margin per point of net-rating gapPlayoffs minus regular season+0.44 (+0.27 to +0.60)
Altitude in Denver and Utah
Their home edges are the league's largest. Visitors' fourth-quarter fade is unclear on its own but shows on the second night of a back-to-back.
−4−20net points per 100, 4th quarter vs first threeVisitors' 4th quarter at altitude−1.4 (−3.3 to +0.2)Extra drop on a back-to-back−2.6 (−4.4 to −0.6)
Back-to-backs cost more now
A back-to-back costs a team about 2.6 points of margin since 2021-22, up from 1.7.
−3−2−10points of margin vs the pre-game expectation1997-98 to 2020-21−1.72 (−1.93 to −1.52)2021-22 to 2025-26−2.64 (−3.20 to −2.04)
Schedule density
Tough stretches wear teams down beyond back-to-backs: each extra game in the past week costs about 0.34 points of margin, about a fifth of a back-to-back, and it shows up on defense.
−2−10points of margin vs the pre-game expectationBack-to-back, beyond other schedule load−1.67 (−1.91 to −1.41)Each extra game in the past 7 days−0.34 (−0.50 to −0.21)Same, held-out seasons 2015-16 on−0.41 (−0.62 to −0.17)
Playing hurt
Hand and shoulder injuries cut true shooting (about 1.3 and 1.6 points); ankle and knee injuries, and the average listing, do not move it.
−3−2−101true-shooting points vs his own healthy gamesHand, wrist, finger or thumb−1.3 (−2.4 to −0.3)Shoulder−1.6 (−3.2 to −0.1)Ankle or knee+0.2 (−0.4 to +0.8)Every listed injury−0.2 (−0.6 to +0.1)
Drawing fouls is a skill
Season to season, how often a player draws fouls is as stable as his free-throw percentage.
0.750.80.850.9same player, one season to the next (correlation)Free-throw % (the reference skill)+0.82 (+0.80 to +0.83)Free-throw rate+0.84 (+0.83 to +0.85)Shooting fouls drawn per shot+0.86 (+0.85 to +0.87)
Playoff risers
Playoff stars are mostly regular-season stars (correlation 0.83). Some players repeatably take on more scoring in the playoffs and hold their production better than others, but the edge is small, it is not in shooting efficiency, and one postseason's lift is about 4% player and 96% noise.
−0.100.10.20.3correlation of a playoff lift with the nextpostseason'sGame Score lift (opponent-adjusted)+0.05 (+0.01 to +0.08)Usage lift+0.18 (+0.14 to +0.23)True-shooting lift−0.03 (−0.07 to +0.01)Teams beating their regular season+0.06 (−0.02 to +0.14)
Starters fade after about nine minutes
Players who average 20+ minutes make shots worth 2.3 points per 100 fewer at nine or more straight minutes on the floor than at three to six (2.0 to 2.7).
0-11-33-66-99+−2−101minutes into his current stint on the floorpoints per 100 shots vs expected
The two-for-one has faded
Quarter-end two-for-ones rose through the 2000s, jumped in 2008-09 and stayed high until 2022-23; since then teams go for them less. Why is not yet tested.
00-0108-0916-1724-2510141822season% excess early shots
Hunted defenders
Offenses go after the same defenders season after season (correlation 0.66), but being hunted does not mean being scored on efficiently (correlation 0.01).
00.250.50.751correlation, regular seasons 2017-18 to 2024-25How often offenses go at him, season to season+0.66Hunted more vs scored on more per attempt+0.01

3What I'm working on further

An analytics department can give the decision makers in the front office invaluable tools. Here are a few, each marked built or proposed.

The model, in depth

0.81correlation with next season's team net rating
0.98slope: a point of forecast is a point of margin (90% interval 0.93 to 1.03)
0.60the same correlation using last season's team net rating

Add up each player's prior-season SiPM, weighted by the minutes he went on to play, and you get the team's next-season net rating almost point for point. It uses the real minutes, so it tests the ratings, not a minutes forecast.

SiPM against two leading public models
Comparison and replayDatesDifference (90% interval)Reading
SiPM minus DARKOevery game day, 2025-26135+0.14 (−0.17 to +0.38)level
SiPM minus DARKOevery week, 2025-2621+0.19 (−0.16 to +0.39)level
SiPM minus DARKOevery week, 2024-2521−0.25 (−0.56 to +0.12)level
SiPM minus DARKOevery week, 2023-2421−0.01 (−0.37 to +0.25)level
SiPM minus EPMgame days with an archived EPM, 2025-2622+0.07 (−0.10 to +0.24)level
SiPM minus EPMweeks with an archived EPM, 2025-263+0.12 (−0.09 to +0.30)level

Score: how much of the error in forecasting the next 30 days of game margins each model's ratings remove, in percentage points; above 0 favors SiPM. "Level" means the interval includes 0.

Like other impact models, it overvalues non-creating bigs and undervalues primary creators. Finding the underlying cause of these residuals, and framing the data and the analysis accordingly, is a primary focus of this work.

Figure 3

EPM re-issued its 2025-26 ratings with a wider spread; the benchmark stands because it scored what EPM published at the time

0.60.70.80.91rank correlation, 2025-26 players with 500+minutesNew EPM vs old EPM0.91 (0.90 to 0.93)SiPM vs old EPM0.87 (0.84 to 0.89)SiPM vs new EPM0.85 (0.82 to 0.88)3-season RAPM vs old EPM0.70 (0.64 to 0.74)3-season RAPM vs new EPM0.75 (0.70 to 0.78)
The benchmark against EPM still stands. Between October 7 and 20, 2026, EPM's publisher replaced its 2025-26 ratings with a version whose spread is 14% wider (10 to 17%), though the order barely moved. The replays in the table above scored saved copies of what EPM published on each date, so a later refit does not change them.

Dot: rank correlation. Bar: 90% interval, players resampled. Filled: old version; hollow: new version.

Figure 4

Preseason games carry real signal, most for rookies, and counting them makes every player forecast more accurate

A. What preseason adds to next season's forecast
00.10.20.30.4out-of-sample R² added by preseason boxscoresBox-score impact,rookies+0.14 (+0.09 to +0.18)Box-score impact, years2-3+0.02 (+0.01 to +0.04)Box-score impact,veterans+0.03 (+0.02 to +0.04)Points per 36, rookies+0.29 (+0.23 to +0.35)Points per 36, years 2-3+0.05 (+0.04 to +0.07)Points per 36, veterans+0.03 (+0.03 to +0.04)
B. Forecast error, a preseason minute counted as 0.7 of a regular-season minute
−30−20−100% change in forecast error (below 0 = moreaccurate)Season rating (SiPM)−0.5 (−0.8 to −0.2)Trajectory: impact−3.2 (−4.0 to −2.4)Trajectory: minutes−2.9 (−3.5 to −2.2)Short-term: points−8.5 (−9.9 to −7.2)Short-term: threes tried−25.8 (−27.9 to −23.6)
Preseason box scores say the most about rookies. For a rookie's box-score impact they add 0.14 of R² to a forecast built on draft slot and age; for returning players the gain is small but real. Counted at 0.7 of a regular-season minute, preseason makes all three player forecasts more accurate in walk-forward tests, and the short-term box-score forecast improves on all 14 stats. This preseason, the largest upward flag among returning players belongs to the Bulls' Leonard Miller: +1.54 on his box-score impact forecast.

R²: the share of next season's variation a forecast explains. Rookies are compared with draft slot and age; returning players with last season, age and years in the league. Walk-forward: each season is forecast from earlier seasons only. Bar: 90% interval, players resampled.

Trajectories, in more detail

Figure 5

From 27 to 31, explosive traits fall while skills barely do; after 31 both fall

−0.3−0.2−0.100.1four-year change, in league spreads (groupaverage)Explosive traits, age 27to 31−0.20 (−0.23 to −0.17)Skill traits, age 27 to31−0.03 (−0.11 to +0.06)Explosive traits, age 31to 35−0.21 (−0.26 to −0.16)Skill traits, age 31 to35−0.14 (−0.25 to −0.04)
A skill-based game loses less through the late 20s, but not past the early 30s. From 27 to 31 the explosive group falls 0.20 league spreads and the skill group 0.03, a gap of −0.18 (−0.27 to −0.08); from 31 to 35 the explosive group falls 0.21 and the skill group 0.14, a gap not distinguishable from zero.

Dot: estimate. Bar: 90% interval. Explosive group: rim share, dunks, transition share, free-throw rate, blocks, offensive rebounds. Skill group: three-point %, free-throw %, mid-range %, assists, ball security.

Figure 6

Offense rises fast when young and falls from the late 20s; measured defense barely moves

Offensive impactDefensive impact
22 and under23-2425-2627-2829-3031-3233+−0.5−0.2500.250.50.75age at the start of the seasonchange in impact per 100, next season
Defense is not the first thing to go, though the measure may be too blunt to see it go. Offensive impact rises 0.58 points per 100 a season at 22 and under, stops rising by 25-26 and falls 0.54 a season at 33 and over. Measured defense moves far less: +0.13 when young and −0.02 when old.

Dot: average change from one season to the next. Bar: 90% interval. Every player with 1,000+ minutes in the earlier season who plays 250+ in the next counts once; players likely to drop out are weighted up, using only what was known that season.

Figure 7

Breakouts come young; defensive ones come about two years later than offensive ones

Offensive breakoutsDefensive breakouts
≤202122232425262728293031+0246810age in the breakout seasonbreakouts per 100 player-seasons
Do not write off a young player's defense at 23. 52% of offensive breakouts come at 23 or under, against 33% of defensive ones (median age 23.9 against 25.7). Most of a breakout is not forecast: for an overall-impact breakout the forecast expected a median 18% of the rise, though the definition builds in some surprise. Young high picks are about five times over-represented among those breakouts, and a change of team is under-represented (0.53 times).

A breakout is a one-season rise in the top 2.5% against the player's own past. Dot: rate. Bar: 90% interval.

Figure 8

A plateau at 23 is often a pause; at 30 it is usually the level

23 and under24-2526-2728-2930+01020304050age when the plateau ends% of plateaus followed by a rise
The chance of a rise after a plateau falls from 42% when it ends at 23 or under to 4% at 30 and over. Of 2,184 plateaus, 335 were followed by a rise larger than the forecast expected, often on another part of the game such as usage or creation.

Plateau: two or more flat seasons. Dot: share. Bar: 90% interval.

A related caution, for players 22 and under: a young player on a strong team can look worse than he is. Each extra point per 100 in his four teammates' combined prior-season rating lowers his measured impact by 0.125 per 100 (0.078 to 0.168).

From the front office to the bench

Figure 9

A player's first shot after checking in is his worst, especially in the team's first possession

A. By minutes since entry
0-11-22-33-55-88+−4−3−2−101minutes since he checked in (3-5 = comparison)points per 100 shots vs expected
B. By shot order and possession
−4−3−2−10points per 100 shots vs expected (his own 3rdand later shots = 0)First shot after amid-quarter entry−1.91 (−2.20 to −1.64)Second shot−0.21 (−0.51 to +0.08)First shot, in theteam's first possession−3.86 (−4.37 to −3.42)First shot, in a laterpossession−1.50 (−1.78 to −1.22)Starters' first shotafter halftime−0.04 (−0.51 to +0.37)
A player's first shot after a mid-quarter entry is worth 1.91 fewer points per 100 shots than his own later shots, after accounting for shot type, location and his skill. The first minute is worst (about 3 points), and the dip is gone after about three minutes. It is worst in the team's first possession after he enters (−3.86), against −1.50 in a later possession. The effect is small: about 0.3 points a game for a team. Moving that first-possession shot to someone else could recover 0.06 to 0.10 a game. Whether to act on it is the coaching staff's call.

Every regular-season shot 1996-97 to 2025-26. Dot: estimate. Bar: 90% interval. The recovery is 0.06 a game if his first shot moves to a later possession, and 0.10 if an average shot replaces it. The possession split is not tested on fresh data, and coaches may call plays for players they expect to be guarded poorly. Starters coming out of halftime, after a warm-up, show no dip. A player's own dip does not repeat from season to season, so it is no use for rating players.

Figure 10

When a teammate's absence hands a player a bigger role, his true shooting falls, mostly from losing the teammate who set him up

A. The cost, by how it is measured
−1−0.50true-shooting points per extra usage pointUsage handed over by ateammate's absence−0.52 (−0.61 to −0.42)Usage handed over byroster changes−0.59 (−0.77 to −0.36)Same player, season toseason, any cause−0.07 (−0.10 to −0.04)Comparing differentplayers−0.01 (−0.04 to +0.03)
B. Who pays it (teammate-absence test)
−2−10true-shooting points per extra usage pointOn-ball creators−0.16 (−0.27 to −0.05)High-usage finishers−0.33 (−0.49 to −0.18)Mid-usage players−0.37 (−0.54 to −0.21)Spacers−1.26 (−1.69 to −0.87)Low-usage interiorplayers−1.49 (−2.12 to −1.03)
When a teammate's absence or a roster change hands a player a bigger role, his true shooting falls 0.52 to 0.59 points per usage point. Comparing players shows almost no cost, because coaches give the ball to the players who can carry it. In the teammate-absence test, most of the cost is losing the teammate who set him up; with that passing held fixed, the extra shots cost little: −0.06 (−0.21 to +0.08). The roster-change test cannot split the cost this way. On-ball creators pay little; spacers and interior players pay a lot. Usage is a resource to fit together as each player's efficiency develops.

Dot: estimate. Bar: 90% interval. Teammate-absence test: 1996-97 to 2025-26. Roster-change test: 2022-23 to 2025-26.

Figure 11

Leaving a starter in after an early second foul is worth about a third of a point of win probability; coaches lose about 0.3 wins a season by sitting

00.10.20.30.4win probability gained by leaving him in,percentage points per decision2nd foul, 1st quarter+0.33 (+0.28 to +0.38)same, minutes given back+0.17 (+0.14 to +0.19)3rd foul before half+0.11 (+0.09 to +0.13)same, minutes given back+0.16 (+0.14 to +0.19)4th foul, 3rd quarter+0.12 (+0.10 to +0.14)same, minutes given back+0.13 (+0.11 to +0.15)5th foul, 4th quarter+0.06 (+0.05 to +0.07)same, minutes given back+0.17 (+0.14 to +0.20)
Leaving a starter in usually pays. After a second foul in the first quarter it adds +0.33 points of win probability (+0.28 to +0.38), or +0.17 once the minutes coaches give back later are counted; sitting is right only when the substitute is rated better than the starter. Coaches' actual choices give up 0.30 wins per team per season (0.27 to 0.32), almost all by sitting.

Value: the win value of a point of margin, times the starter's edge over the teammates who replace him, times the extra minutes he plays. 103,235 trouble events, 1996-97 to 2025-26. Billy Donovan's leave-in rate is close to the league average. Bar: 90% interval, players resampled; it covers sampling, not the model's assumptions.

Figure 12

After a kick-out, the catch-and-shoot three beats passing, but by less than half the raw gap once the situation is held fixed

−0.200.20.4points per kick-out, catch-and-shoot threeminus each choiceShot vs any pass+0.08 (0.00 to +0.16)same, raw difference+0.20 (+0.13 to +0.26)Shot vs drive again+0.08 (−0.01 to +0.17)same, raw difference+0.20 (+0.14 to +0.26)Shot vs pass, under 1 s+0.12 (+0.03 to +0.21)same, raw difference+0.19 (+0.12 to +0.27)Shot vs pass, 1-2 s−0.11 (−0.24 to +0.01)same, raw difference+0.01 (−0.11 to +0.12)Shot vs pass, 2+ s+0.18 (+0.03 to +0.34)same, raw difference+0.31 (+0.17 to +0.46)
The catch-and-shoot three is still the best choice after a kick-out, but by less than the raw numbers suggest. Its raw edge over any pass, +0.20 points per kick-out, falls to +0.08 (0.00 to +0.16) once the catcher's space, the defenders, the clocks and the score are held fixed. A pass held one to two seconds scores about as well as the shot, and always following the model's best choice would add only +0.03 points (−0.03 to +0.10).

From player tracking of 631 games, October 2015 to January 2016: 136,735 perimeter catches, 7,243 of them after a drive. The estimate combines a model of who chooses what with a model of the points each choice produces. Filled: situation held fixed; hollow: raw difference. Bar: 90% interval, games resampled.

Figure 13

Rotation stability is a coach's habit that follows him to new teams; stable seasons go with better results, but nothing shows the habit causes them

A. Stability follows the coach
00.20.40.60.8correlation of a team's rotation stability, oneseason to the nextSame coach, next season0.54 (0.46 to 0.62)After a coaching change0.06 (−0.09 to 0.21)Coach at his new team(40 moves)0.33 (0.08 to 0.56)
B. Stability and results
−2−10123net rating per 100 possessions, per SD ofrotation stabilityRaw, no rosteradjustment+2.47 (+2.12 to +2.83)Beyond the roster'sprior ratings+1.23 (+0.94 to +1.55)Plus injuries and rosterchurn+0.68 (+0.42 to +0.96)Within one coach's spell+0.57 (+0.26 to +0.94)The coach's own habit+0.30 (−0.46 to +1.05)A coach arrives at a newteam−0.89 (−2.13 to +0.23)
Rotation stability belongs to the coach, and nothing shows it costs young players. With the same coach it carries over at r = 0.54; after a coaching change, 0.06. Steadier teams beat their roster's expectation by +0.68 per 100 per SD (+0.42 to +0.96), but the designs that isolate the coach find nothing, so healthy, winning teams likely settle their rotations rather than the reverse. Billy Donovan's Bulls sat about at the league average (0.02 below it on a 0-to-1 scale).

Stability compares each rotation player's minute-by-minute pattern across every pair of games: 1 = the same minutes every night, 0 = random (league average 0.25). Players 23 and under change by −0.15 BPM per SD of team stability (−0.26 to −0.06), the opposite sign to a development cost. 390 team-seasons, 2013-14 to 2025-26. Bar: 90% interval, teams resampled.

Fit: building around a star creator

Figure 14

Spacers and interior bigs fit next to a star creator; two star creators are worth less than the sum of their ratings

A. Next to a star creator, each type adds
−1−0.500.5points per 100 beyond the players' own ratingsSpacer+0.38 (+0.26 to +0.54)Role player+0.34 (+0.20 to +0.47)Interior big+0.30 (+0.12 to +0.49)Playmaking big0.00 (−0.25 to +0.23)Scorer−0.09 (−0.26 to +0.06)Other creator−0.36 (−0.52 to −0.22)A second star creator−0.91 (−1.22 to −0.57)
B. Title and series odds with a lead option who shoots at least league average
0123multiple of the odds a team's ratings give it (1 = no edge)Title odds×1.86 (1.12 to 3.18)Series odds×1.55 (1.24 to 1.93)
C. Stacking primary ball handlers: the second adds little on offense and costs in full on defense
0123points per 100 beyond the five players'ratings, vs no primary handlerOne primary handler:points scored+2.09 (+1.75 to +2.46)One primary handler:points allowed+0.51 (+0.22 to +0.81)Two: points scored+2.84 (+2.41 to +3.32)Two: points allowed+0.80 (+0.43 to +1.17)Three or more: pointsscored+2.22 (+1.46 to +2.97)Three or more: pointsallowed+0.79 (+0.20 to +1.36)
Next to a star creator, spacers add 0.38 points per 100 beyond their own ratings and interior bigs 0.30; two star creators together are worth 0.9 per 100 less than their ratings add up to. Pair effects held up in later seasons at 1.21× their size (0.69 to 1.71). Teams with a lead option who shoots at least league average won 32 titles; their ratings and playoff brackets predicted 26.7. As a group they were already favorites, so multiplying their odds by 1.86 adds about five titles over 46 seasons. Without the shooting condition the multiplier is ×1.46 (0.85 to 2.67), which cannot be told apart from no edge. A forward test on the 2008-26 playoffs was too small to confirm the gain. Panel C: lineups with one primary ball handler score 2.1 more per 100 than their ratings predict; a second handler adds only 0.8 more, while the points allowed keep rising (+0.51, then +0.80). Sharing the ball does not buy the defensive cost back.

Star creator (panel A): usage at least one standard deviation above average and offense in the season's top 10%. Lead option (panel B): a regular-minutes player whose league usage rank is at most half the number of teams (15th with 30 teams) and whose true shooting is at or above league average. Dot: estimate. Bar: 90% interval. Pairs: lineups 1996-97 to 2025-26. Titles: playoff teams 1980-81 to 2025-26.

Figure 15

Lineups with more switchable defenders allow fewer points than their ratings predict

A. By number of switchable defenders
−0.500.51fewer points allowed per 100 than ratingspredict, vs noneOne switchable defender−0.10 (−0.51 to +0.28)Two+0.18 (−0.30 to +0.71)Three or more+0.81 (+0.34 to +1.29)
B. Per standard deviation of lineup switchability
00.20.40.6fewer points allowed per 100, per standarddeviationSwitchability measuredthe same season+0.28 (+0.12 to +0.45)Measured the seasonbefore+0.20 (+0.04 to +0.37)
Most of the gain comes with the third switchable defender. Per standard deviation of switchability, lineups allow 0.28 fewer points per 100 than the five players' defensive ratings predict (0.12 to 0.45), and last season's switchability still predicts it. The intervals are wide.

Switchability: how widely the heights of the players a defender guards vary, beyond what his usual assignment predicts; a stable trait (reliability 0.72). NBA.com matchup data 2017-18 to 2024-25. Dot: estimate. Bar: 90% interval.

Defense, and the limits of public data

Figure 16

Award votes add defensive signal the numbers miss; public data captures about half of the signal in a player's future

A. What award votes add beyond box score and measured defense
−1−0.500.51next season's defense, points per 100, beyondbox score and measured defenseAll-Defensive vote share(0 to 1)+0.67 (+0.39 to +1.01)Any vote, but notselected+0.15 (+0.09 to +0.21)Defensive Player of theYear vote share−0.22 (−0.92 to +0.34)
B. How much public data can know
Predicted from public dataPredictable at all (signal ceiling)
0%25%50%75%100%share of the variance in a player's next three seasons1998-200438%67%57% of the knowable (47 to 65)2005-1230%63%48% of the knowable (39 to 57)2013-2133%65%50% of the knowable (41 to 58)
All-Defensive votes predict a player's defense next season beyond his box score and measured defense: +0.67 per 100 for a full share, and +0.15 for any vote short of selection. Public data explains 30 to 38% of a player's next three seasons of impact, and 63 to 67% of that impact is signal rather than noise, so public data captures about half of the signal. Better models of public data can close some of the gap; the rest needs data teams hold: tracking, medical, practice and scouting. In the draft, when draft order and a public stats model disagree, draft order wins 56% of the time on four-year value (51 to 62%).

A: 1996-97 to 2024-25; dot: estimate, bar: 95% interval. B: RAPM averaged over the next three seasons; the ceiling is the share of that average that is signal rather than noise, and it has no interval.

Figure 17

Stop% is stable because it is mostly rebounds and blocks; it tracks defensive impact less well than box-score defense and adds nothing to it

A. Stable from season to season
00.250.50.751correlation, same player one season to the nextStop%0.88 (0.86 to 0.89)Box-score defense (DBPM)0.72 (0.70 to 0.74)Defensive rebound %0.92 (0.92 to 0.93)Block %0.91 (0.90 to 0.92)Steal %0.79 (0.77 to 0.80)
B. Tracks measured defensive impact
00.250.50.751correlation with defensive RAPM, same seasonStop%0.33 (0.30 to 0.36)Box-score defense (DBPM)0.50 (0.48 to 0.53)Defensive rebound %0.12 (0.09 to 0.16)Block %0.17 (0.14 to 0.21)Steal %0.23 (0.20 to 0.26)
Stop% tracks measured defense less well than box-score defense (0.33 against 0.50) and adds nothing to it. Added to box-score defense, it changes next-season prediction error by −0.01% (−0.06% to +0.05%). It is as stable as the rebound and block rates it is built from: 85% of the 20 career leaders are big men, against 23% of all 819 players with 5,000+ minutes since 2003-04.

Stop%: Dean Oliver's individual stop rate, rebuilt from box scores; about 60% of it is the team's forced misses and turnovers, shared out by minutes. Player-seasons with 1,000+ minutes, 2003-04 to 2025-26; out-of-sample test fit on 2003-13 and scored on 2014-24. Bar: 90% interval, players resampled.

Central questions, tested

Figure 18

Gravity: a small effect, clearest on above-the-break threes

−0.0500.050.1next-season correlation of teammates'shooting luck, players who changed teamsAll teammate threes+0.040 (+0.006 to +0.075)Above-the-break threes+0.056 (+0.020 to +0.093)Corner threes0.000 (−0.038 to +0.037)Free throws (the check)+0.029 (−0.006 to +0.066)
The evidence for gravity is suggestive, not settled. When a player changes teams, his new teammates' threes beat their norms in the same direction they did on his old team: weakly for all threes, more clearly above the break, not in the corners. The all-threes correlation (0.040) barely clears what random teammates produce by chance (0.038), and the free-throw check, where gravity should not show, is smaller (+0.029) but not zero, which weakens the result. A typical player's true effect is about 0.47 percentage points on each teammate three, but one season of the measure is about 98% noise. Several seasons, or tracking data, would settle it.

Dot: correlation. Bar: 90% interval. Free throws are the check because nobody guards them.

Figure 19

Leads are less safe than they used to be: an older win-probability model is overconfident on recent games

Fit on 1996-97 to 2015-16, tested on 2016-17 to 2025-26Model with era terms
0255075100−4−2024win probability the model gave (%)actual minus predicted win rate (points)
Leads are less safe than they used to be, so late-game decisions should use a model fit on the current era. A model built from score, clock and possession on 1996-97 to 2015-16 games is too confident on newer games: when it gave a team 85%, that team won 81%. Its odds need pulling back toward even by about a sixth (a slope of 0.83, where 1.00 means no correction). The model with era terms is closer but still off by about 2 points: when it gave a team 25%, that team won 27%, and when it gave 75%, it won 73%. Each season on its line is scored by a model fit on the other seasons, so it has already seen the current era.

Each point is one of ten bins of predicted win probability. 0 = perfectly calibrated; below 0 on the right means favorites won less often than the model said.

Figure 20

Threes versus twos: in the half court, fully counted, they are even, and the balance can be tracked every season

A. Three minus two, every season
All shots, free throws countedHalf court, rebounds and next trip counted
1997-982004-052011-122018-192025-26−0.100.10.2season (start year)three minus two, points per attempt
B. By kind of two, 2025-26
−0.200.2points per attempt, 2025-26 (above 0 =the three is worth more)Three vs shot at the rim−0.314 (−0.325 to −0.304)Three vs average two−0.093 (−0.102 to −0.083)Three vs average two,half court, full accounting+0.009 (−0.006 to +0.024)Three vs short two+0.100 (+0.089 to +0.111)Three vs long two+0.222 (+0.208 to +0.237)
In the half court, once offensive rebounds and the opponent's next trip are counted, threes and twos are even (+0.009, −0.006 to +0.024): NBA teams have found the balance. Across all shots, counting free throws but not rebounds, the average two returns 0.09 points per attempt more than the average three, so it can look as if teams take too many threes; leaving out putbacks and fast breaks removes about 60% of that lead. Shots at the rim are the only twos worth more than a three: get to the rim, and do not trade threes for midrange twos.

Band and bar: 90% interval. Half court excludes transition, putbacks, heaves and garbage time.

Figure 21

Crashing the offensive glass costs almost nothing in transition: each 5 points of offensive rebound rate nets about 6.6 points per 100 misses

00.020.040.060.080.1opponent points per possession after yourmiss, per +5 points of offensive reboundrateAcross teams+0.002 (−0.007 to +0.011)Plus a defense-qualitycontrol+0.007 (−0.001 to +0.014)Player rebounds only+0.003 (−0.006 to +0.013)With missed final freethrows0.000 (−0.010 to +0.010)Same team, year to year−0.001 (−0.011 to +0.009)Cost that would cancelthe gain+0.086
Crashing the offensive glass barely costs anything in transition. For every 5 points of offensive rebound rate a team adds, opponents score +0.002 points per possession after its misses (−0.007 to +0.011), far below the +0.086 that would cancel the extra rebounds; counting the opponent's next possession, the net gain is +6.6 points per 100 misses (5.6 to 7.5). Offensive rebound rate on misses has risen every season, from 26.0% in 2020-21 to 29.9% in 2025-26.

664,302 missed field goals in 180 team-seasons of play-by-play, 2020-21 to 2025-26. Bar: 90% interval, franchises resampled. Blind to how many players crash; that needs tracking.

Figure 22

Team pace habits are stable, but playing faster with the ball does not buy offense

−1−0.500.5offensive rating per 100, per +1 SD, beyondpace and last season's offenseShorter touches−0.16 (−0.48 to +0.08)Fewer dribbles per touch−0.06 (−0.37 to +0.16)More passes per 100−0.43 (−0.75 to −0.23)More drives per 100−0.40 (−0.71 to −0.10)Faster offensivemovement−0.45 (−0.77 to −0.24)Higher pace+0.03 (−0.26 to +0.33)
Playing faster with the ball does not buy offense. Touch length and passes per 100 are stable team habits (r = 0.63 each, year to year), more than pace (0.55), but more passes, more drives and faster movement each go with slightly worse offense, about −0.4 per 100 per SD, and pace shows nothing (+0.03). The likely reason runs the other way: teams with a star creator hold the ball and score well.

390 team-seasons, 2013-14 to 2025-26, from NBA.com team tracking. Six habits were tested, so one chance result is possible. Bar: 90% interval, franchises resampled.

Figure 23

No measurable playoff penalty for an isolation and pick-and-roll style: those plays hold up better than others, and series results show no clear cost

A. The same players' plays, regular season to playoffs
−0.08−0.040playoff minus regular-season points perpossession, opponent-adjustedIsolation +pick-and-roll−0.009 (−0.018 to +0.002)All other play types−0.024 (−0.031 to −0.017)Pick-and-roll handler−0.007 (−0.018 to +0.004)Off screen−0.011 (−0.040 to +0.017)Pick-and-roll roll man−0.011 (−0.039 to +0.015)Isolation−0.012 (−0.030 to +0.007)Spot-up−0.017 (−0.030 to −0.004)Transition−0.022 (−0.034 to −0.010)Cut−0.030 (−0.049 to −0.013)Post-up−0.031 (−0.053 to −0.008)Handoff−0.050 (−0.084 to −0.015)Putback−0.068 (−0.095 to −0.042)
B. Playoff games and series
−4−202points per 100 vs expectation, per +10 pointsof isolation + pick-and-roll shareMain test, 2015-16 to2025-26−0.89 (−2.33 to +0.56)Plus star-qualitycontrols−0.34 (−1.88 to +1.19)1996-97 to 2014-15,stand-in+0.27 (−0.88 to +1.41)All 30 seasons, stand-in−0.60 (−1.56 to +0.36)Fades late in a series?+0.28 (−2.26 to +2.83)Worse against gooddefenses?+0.37 (−0.36 to +1.11)
Isolation and pick-and-roll plays hold up in the playoffs better than other plays. From the regular season to the playoffs, a player's isolation and pick-and-roll plays change by −0.009 points per possession (−0.018 to +0.002), against −0.024 for his other plays. A team whose isolation and pick-and-roll share is 10 points above its opponent's does −0.89 per 100 against expectation (−2.33 to +0.56), which rules out a series-win penalty larger than about 13 points; two secondary versions lean negative with intervals that just exclude zero, so a small penalty remains possible.

Synergy play types, 2015-16 to 2025-26. Stand-in: each team's share of unassisted made shots (r = 0.76 with the Synergy share). A: 90% interval, players resampled; hollow dots are single play types. B: 90% interval, allowing games from one team-season to be correlated.

How ideas get tested

820questions tested
304answered no
82mixed
434answered yes
Figure 24

Tested and dropped: popular ideas the data does not support

Each idea sounds right and failed a fair test: the dot sits at or near no effect, or on the wrong side. Three point clearly the wrong way: teams facing elimination play slightly below their level, a bigger role slightly lowers bench players' shot-making, and hunted defenders are not scored on more efficiently. Length still matters on defense: longer players defend better, even though taller guards do not.

Dot: estimate. Bar: 90% interval. Each row has its own scale; the vertical line marks no effect (equal say for pace).

Teams facing elimination play above themselves
points per game (below 0: plays below its level)
−0.97 (−1.81 to −0.12)−220
The faster team sets the pace
faster team's share of control (0.5 = equal say)
0.493 (0.483 to 0.503)0.450.550.5
Being pulled off your own pace hurts your offense
points per 100 per 3 possessions of mismatch
+0.05 (−0.09 to +0.18)−0.40.40
Taller guards defend better
defensive impact per 100 per inch of guard height
−0.04 (−0.13 to +0.04)−0.30.30
Playoff offenses score more per shot on the weak defenders they hunt
extra playoff points per attempt per SD weaker defense (a cost would be above 0)
−0.013 (−0.019 to −0.007)−0.040.040
A bigger role makes a player shoot better
bench shot-making per 100 shots, per 10 points of extra role
−0.52 (−0.83 to −0.21)−1.21.20
Clutch is a trait
late-and-close edge, next-season correlation
+0.02 (−0.03 to +0.07)−0.20.20
Stars get a reputation whistle
extra free throws per shot vs look-alikes after a first All-NBA team; at the edge of zero, and the shooting-foul rate does not move
+0.010 (0.000 to +0.021)−0.040.040
Regular-season rest pays off in the playoffs
playoff true-shooting points per 3 fewer minutes a game
+0.04 (−0.11 to +0.22)−0.40.40
A college stat beats draft slot
0 of 15 out-of-sample tests
0 of 15
College shooters struggle to make it in the NBA
extra NBA minutes in the first three seasons vs draft slot, shooters minus other picks, 2018-23 classes
+330 (−23 to +669)−8008000
Style uniqueness predicts stardom
change in All-NBA forecast precision (no interval saved)
−0.039−0.10.10
Figure 25

Qualitative history, quantified: every change to the game, dated

88 changes to the game (87 dated), 1979-80 to 2026-27
19801990200020102020season the change took effect (2020 = 2020-21)Rules (19)1979-80: Three-point line added1994-95: Three free throws for a foul on a three-point shot1994-95: Three-point line shortened to 22 ft1994-95: Hand-checking restricted (backcourt and above the free-throw line)1997-98: Three-point line restored to original distance1997-98: Restricted-area arc (no-charge zone) added1999-00: Hand-checking curbed and five-second back-down rule (committee changes)2001-02: Backcourt count cut from 10 to 8 seconds2001-02: Illegal defense abolished: zone allowed, defensive three seconds added2004-05: Hand-checking crackdown on the perimeter2006-07: Synthetic game ball (reverted mid-season)2013-14: Replay expanded (restricted area, shooting motion) and clear-path tweak2016-17: Away-from-the-play foul rule extended to every quarter (anti 'hack-a')2017-18: Timeouts cut from 18 to 14; 15-minute halftime2018-19: Shot clock resets to 14 after an offensive rebound; clear path simplified2019-20: Coach's challenge2022-23: Transition take foul: one free throw plus possession2023-24: In-game flopping technical; second challenge after a win2024-25: Challenge on out-of-bounds can find a missed foulOfficiating (5)1988-89: Third referee added2012-13: Post-game flopping fines2015-16: Freedom-of-movement memo (March 2016)2018-19: Freedom of movement (2018-19 points of education)2021-22: Non-basketball moves no longer draw foulsLeague (20)1980-81: Expansion: Dallas Mavericks (23 teams)1983-84: Playoffs expanded to 16 teams1984-85: Finals switch to 2-3-21988-89: Expansion: Charlotte Hornets and Miami Heat1989-90: Expansion: Orlando Magic and Minnesota Timberwolves (27 teams)1995-96: Expansion: Toronto Raptors and Vancouver Grizzlies (29 teams)2001-02: Grizzlies move to Memphis2002-03: Hornets move to New Orleans2002-03: First round becomes best-of-seven2004-05: Charlotte Bobcats join; six-division realignment2006-07: Top-four seeds ordered by record2008-09: SuperSonics move to Oklahoma City2013-14: Finals return to 2-2-1-1-12015-16: Seeding by record only2017-18: Player resting policy2019-20: Season suspended; Orlando bubble2020-21: Limited crowds in 2020-212020-21: Play-in tournament2023-24: In-season tournament (NBA Cup)2023-24: Player participation policy and 65-game award ruleSchedule (5)1998-99: Lockout: 50-game season2011-12: Lockout: 66-game season2015-16: Back-to-back reduction begins2017-18: No four-in-fives; earlier start2020-21: 72-game season starting Dec. 22, 2020CBA and money (12)1984-85: Draft lottery begins (equal odds)1989-90: Weighted lottery1993-94: Lottery odds steepened (worst team 25%)1998-99: 1999 CBA: maximum salaries, rookie scale, luxury tax2006-07: Age limit: 19 and one year out of high school2011-12: 2011 CBA: 51.2% BRI, repeater tax, amnesty2016-17: Salary-cap spike2017-18: 2017 CBA: two-way contracts, designated veteran extension2018-19: Flatter lottery odds (three worst teams 14%)2023-24: 2023 CBA: first and second aprons2024-25: Second-apron draft-pick freeze begins2026-27: Announced: '3-2-1' lottery (worst three teams 5.4%)Data (10)1996-97: Threes recorded at 0 ft1996-97: Play-by-play starts in Singular's database2000-01: Shot-type words tied to makes before 2022-232013-14: SportVU tracking in every arena2013-14: 'Take' foul label appears in the feed2017-18: Second Spectrum replaces SportVU2017-18: NBA.com matchup data start2019-20: Rest and injury-management labels start2023-24: Hawk-Eye tracking2025-26: End-of-quarter heaves no longer count as player missesStrategy (17)2001-02: Zone defense legal (rule)2004-05: Hand-check ban on the perimeter (rule)2004-05: End-of-quarter two-for-one2005-06: Giving up the offensive glass for transition defense2012-13: Pace and space2012-13: The mid-range retreat2014-15: Intentional fouling of poor free-throw shooters (and the 2016-17 rule)2016-17: Stretch bigs / five-out2016-17: Sitting starters with two early fouls2017-18: Switching everything2017-18: Load management2018-19: Small-ball centers2020-21: Return to the offensive glass2020-21: Transition take fouls (and the 2022-23 rule)2022-23: Hunting the weakest defender2022-23: Two-for-one fading
Any trend over time is read against what changed in its window: rule changes, officiating memos, CBA terms, data-feed changes and strategy shifts, each dated. On the web version, hover over a dot to see the change.

When a provider quietly changes its data, the inputs get re-checked

After the project's September pull, NBA.com re-issued its 2024-25 player-tracking data on its newer Hawk-Eye definitions, with no public note. A routine analysis caught it as a sudden jump in one season; the 24 affected files were re-pulled with backups, and the results built on them were re-run. No headline finding flipped: the shot-making rating still tracks the NBA's own Hawk-Eye shot-making (correlation 0.71 before, 0.70 after). One stability measure moved (drive fouls drawn, year to year: 0.74 to 0.57) because the new files leave the free-throw fields nearly empty; those fields are now blanked or flagged.

The idea the project is named after did not hold

Singular started from a hunch: the NBA, more than other sports, runs on singular talents, so a player whose style is unlike anyone else's should be likelier to become a star. Tested on future All-NBA players, style uniqueness slightly hurt the forecast, and a machine-learned style profile did worse.

That version of the idea could not be proven with public data alone. But the best players in the league plainly each have a unique game, so the nature of top talent remains a guiding principle. There is something there, and it is what I want to keep pursuing.

Prepared October 2026. Intervals are 90% unless a figure says otherwise. PDF version.