Game quality

What each result was worth beyond the score. Every play is graded by EPA (expected points added), then adjusted for who it came against: a defence's rating is what it allowed to everyone else that season, so a big day against a bad defence counts for less. Season views include playoff games.

Justin Herbert — 2022

Adj EPA / dropback
+0.024
Raw EPA / dropback
+0.041
Dropbacks
782
Turnover EPA
-66.5
WPA
+0.88
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1LV 34 +0.373 +0.440 -0.067 +12.7 0 / 0 +0.0 0 +0.0 +0.27 +6.4
2KC 50 -0.029 -0.018 -0.010 -1.4 1 / 0 -13.0 2 -3.6 -0.27 +4.2
3JAX 46 -0.262 -0.197 -0.065 -12.0 1 / 1 -11.3 1 -5.0 -0.17 -6.7
4HOU 40 +0.409 +0.418 -0.009 +16.3 0 / 0 +0.0 1 -0.9 +0.43 +4.2
5CLE 35 +0.169 +0.126 +0.043 +5.9 0 / 0 +0.0 1 -1.0 -0.04 +0.3
6DEN 59 -0.245 -0.267 +0.021 -14.5 1 / 0 -5.0 2 -3.7 -0.79 -5.3
7SEA 54 -0.236 -0.192 -0.044 -12.8 1 / 1 -11.9 3 -10.5 -0.16 -4.9
9ATL 43 +0.037 +0.116 -0.078 +1.6 1 / 0 -4.2 0 +0.0 +0.47 -1.4
10SF 37 -0.147 -0.181 +0.034 -5.4 1 / 0 -2.0 2 -2.1 -0.20 -2.5
11KC 35 +0.188 +0.193 -0.004 +6.6 1 / 0 -2.1 5 -6.1 +0.10 +10.8
12ARI 52 +0.049 +0.061 -0.011 +2.6 0 / 0 +0.0 4 -8.4 +0.46 +4.9
13LV 52 -0.091 -0.010 -0.081 -4.7 0 / 0 +0.0 5 -7.3 -0.12 -4.3
14MIA 55 +0.041 +0.031 +0.011 +2.3 0 / 0 +0.0 4 -6.0 +0.23 +7.9
15TEN 43 -0.178 -0.173 -0.005 -7.7 2 / 0 -7.3 3 -6.7 +0.06 +2.7
16IND 35 -0.098 -0.084 -0.013 -3.4 1 / 1 -9.8 4 -8.8 +0.06 +10.9
17LA 28 +0.381 +0.365 +0.016 +10.7 0 / 0 +0.0 0 +0.0 +0.16 +6.8
18DEN 38 +0.443 +0.406 +0.037 +16.8 0 / 0 +0.0 1 -1.0 +0.28 -2.0
19JAX 46 +0.110 +0.166 -0.056 +5.1 0 / 0 +0.0 3 -1.5 +0.08 -7.9
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 2026-09-14 01:25 UTC, from nflverse. Write-up: backtests/nfl_game_quality/FINDINGS.md.