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.

Sam Howell — 2023

Adj EPA / dropback
-0.159
Raw EPA / dropback
-0.153
Dropbacks
679
Turnover EPA
-109.9
WPA
-1.67
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1ARI 37 -0.456 -0.363 -0.094 -16.9 1 / 1 -12.2 6 -14.2 -0.49 -6.9
2DEN 43 +0.152 +0.169 -0.016 +6.5 0 / 0 +0.0 4 -8.8 +0.21 +8.9
3BUF 38 -0.677 -0.696 +0.019 -25.7 4 / 0 -17.3 9 -11.1 -0.31 +0.0
4PHI 46 +0.174 +0.168 +0.006 +8.0 0 / 0 +0.0 5 -6.9 +0.27 +10.4
5CHI 57 -0.008 +0.048 -0.055 -0.4 1 / 0 -4.0 5 -6.1 -0.06 +11.7
6ATL 28 -0.047 -0.007 -0.040 -1.3 0 / 0 +0.0 5 -6.0 +0.09 +1.9
7NYG 48 -0.315 -0.306 -0.009 -15.1 1 / 0 -4.9 6 -10.4 -0.42 -3.2
8PHI 53 +0.071 +0.068 +0.003 +3.8 1 / 0 -5.4 1 -3.5 -0.04 +8.4
9NE 48 +0.144 +0.105 +0.039 +6.9 1 / 0 -5.5 3 -4.2 +0.03 +1.7
10SEA 47 +0.202 +0.248 -0.046 +9.5 0 / 0 +0.0 3 -5.5 +0.35 -2.8
11NYG 49 -0.184 -0.181 -0.003 -9.0 3 / 0 -12.7 4 -4.2 -0.50 +4.6
12DAL 48 -0.232 -0.257 +0.026 -11.1 1 / 0 -9.5 4 -8.4 -0.06 -6.0
13MIA 27 -0.516 -0.482 -0.034 -13.9 1 / 0 -9.3 3 -5.0 -0.27 -8.2
15LA 27 -0.487 -0.466 -0.021 -13.1 1 / 0 -5.0 1 -1.0 -0.24 -22.6
16NYJ 23 -0.947 -1.021 +0.074 -21.8 2 / 0 -10.2 1 -2.3 -0.25 -42.0
17SF 29 -0.270 -0.332 +0.062 -7.8 2 / 0 -8.0 1 -2.9 -0.07 -1.0
18DAL 31 -0.194 -0.220 +0.026 -6.0 2 / 0 -5.7 4 -6.4 +0.08 +0.3
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.