🐻⬇️🏀

Model Card

Box: game totals spread by minutes; cannot separate teammates; for seasons without play-by-play. Sequential Box Elo on negative turnovers per 100 possessions. Positive values mean a player's minutes tend to improve team ball security.

Validation here is out of sample. From two weeks into each season, a model trained on earlier games predicts each following week without learning from that week. Predictions use the players' observed minutes; each point is the minutes-weighted predicted and actual rate in that player's games. When validation was computed, its source snapshot was verified against this published model revision.

Selected League / Season

Change league with the League selector at the top of the page.

Held-out player predictions

Plot Turnovers Box Elo (ball security) against any counting stat (one point per player; choose any season with a served list).

WNBA 2026: 182 players with at least 100 held-out minutes. Across players, predicted and actual correlate at r = 0.94 (weighted by held-out minutes). Across these player averages, weighted R² = 0.83 (relative to the weighted mean of actual held-out outcomes). Per held-out team game, squared error is 12.3% below predicting the league average. Each dot is a player (182 with the most held-out minutes are plotted; larger dots had more); on the dashed line, actual equals predicted. Select a dot for the player.

Held-out miss against playing time

Each dot is a player's actual minus predicted team minus turnovers per 100 possessions in the player's games against their held-out minutes (log scale). Orange points are the minutes-weighted mean miss of eight equal groups of players by playing time: a model that shrinks its low-minutes players too far, or not far enough, shows a slope.

Lineup RAPM vs Box Elo, per season

Both forms of this family are shown side by side wherever a season publishes them; this table is information, not a switch. Each column is the held-out correlation of that form's predictions with the actual per-segment margin (fit before a date, scored on later segments); within two paired standard errors the two predict equally well. Correlations are small in absolute terms: a segment holds about one such event. Held-out correlation does not penalize a Box form for not telling teammates apart; the season links show each form's team share.

Output Coverage

Rows in each model's current published run (or legacy rows where no run is selected).