Game quality
How well each team played, beyond the score: EPA (expected points added) per play, adjusted for the opponent. A big day against a bad defence counts for less. Season views include playoff games.
Bryce Perkins — 2022 Every split →
Adj EPA / dropback
-0.468
Raw EPA / dropback
-0.480
Dropbacks
39
Turnover EPA
-10.9
WPA
-0.37
| Week | Opp | Dropbacks | Adj EPA/db | Raw EPA/db | Schedule | Total adj EPA | INT / FL | Turnover EPA | Sacks | Sack EPA | WPA | CPOE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 10 | ARI | 1 | -1.142 | -1.120 | -0.022 | -1.1 | 0 / 0 | +0.0 | 0 | +0.0 | -0.04 | +9.9 |
| 11 | NO | 12 | -0.302 | -0.376 | +0.074 | -3.6 | 0 / 0 | +0.0 | 3 | -3.2 | -0.12 | -17.3 |
| 12 | KC | 26 | -0.519 | -0.504 | -0.015 | -13.5 | 2 / 0 | -10.9 | 3 | -4.8 | -0.20 | -10.6 |
How the ratings are built
Opponent adjustment. A unit's rating for a game is its average over its other games that season, blended with 16 games' worth of prior (league average plus half of last season's gap from it; 24 games for pass defence, which is noisier). Early in a season that leans on last year; by midseason it is mostly this year. Chosen by how well it predicts a held-out game: it cut that error by about a quarter against no shrinkage, and adjusted numbers agree between odd and even weeks more than raw ones do (team EPA margin r 0.52 → 0.55, defence 0.32 → 0.36, QB EPA/dropback 0.47 → 0.49, 2016–2025).Win expectancy is a logistic fit of wins on EPA margin over 6,036 completed games (it names the winner 86.5% of the time). These describe what happened; one game is not a forecast. Play-by-play credits the quarterback with every sack and dropback, so a bad line shows up in his numbers. Seasons 2016–2026, built 2026-11-07 11:05 UTC, from nflverse. Write-up:
backtests/nfl_game_quality/FINDINGS.md.