🐻⬇️🏀

Player model

Turnovers Box Elo (ball security)

Online player rating for keeping own-team turnovers down.

Status implemented Short Name TO Box Elo sec
Rating Style impact Where Shown player pages, players leaderboard

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. The source inputs were not verified as identical to the published model revision.

Selected League / Season

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

Season

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).

No current held-out results for this selection. Held-out player validation covers APM, RAPM and the Box Elo forms.

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.

League Season Lineup RAPM Box Elo Paired SE Difference Held-out segments
NCAAM 2024-2025 0.061 0.059 0.0023 +0.7 SE (within noise) 73433
NCAAM 2015-2016 0.051 0.054 0.0031 -0.7 SE (within noise) 56157
NCAAM 2014-2015 0.055 0.050 0.0034 +1.2 SE (within noise) 56484
NCAAM 2013-2014 0.061 0.052 0.0027 +3.2 SE 59475
NCAAM 2012-2013 0.064 0.057 0.0029 +2.4 SE 53932
NCAAM 2011-2012 0.054 0.050 0.0021 +1.9 SE (within noise) 53101
NCAAM 2010-2011 0.048 0.043 0.0029 +1.8 SE (within noise) 51034
NCAAM 2009-2010 0.051 0.056 0.0026 -1.9 SE (within noise) 56900
NBA 2025-2026 0.056 0.038 0.0043 +4.3 SE 16855

Output Coverage

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

League Season Rows
WNBA 2026 217
NCAAW 2026-2027 2463
NCAAW 2025-2026 4434
NCAAW 2024-2025 3730
NCAAW 2023-2024 3367
NCAAW 2021-2022 3967
NCAAW 2020-2021 3010
NCAAW 2018-2019 3661
NCAAW 2017-2018 3559
NCAAW 2015-2016 2214
NCAAW 2014-2015 1601
NCAAW 2013-2014 2117
NCAAM 2026-2027 2849
NCAAM 2025-2026 4582
NCAAM 2023-2024 3858
NCAAM 2022-2023 4200
NCAAM 2021-2022 3922
NCAAM 2020-2021 3226
NCAAM 2019-2020 3289
NCAAM 2018-2019 3619
NCAAM 2017-2018 3562
NCAAM 2016-2017 3689
NCAAM 2015-2016 3828
NCAAM 2014-2015 3760
NCAAM 2009-2010 3951
NBA 2026-2027 373
NBA 2024-2025 531
NBA 2023-2024 529
NBA 2022-2023 504
NBA 2021-2022 534
NBA 2020-2021 515
NBA 2019-2020 445