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.

Brock Purdy — 2026 Every split →

Adj EPA / dropback
+0.297
Raw EPA / dropback
+0.291
Dropbacks
217
Turnover EPA
-19.3
WPA
+1.67
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1LA 34 +0.172 +0.142 +0.030 +5.8 1 / 0 -4.6 0 +0.0 +0.32 +0.8
2MIA 22 +0.974 +1.060 -0.087 +21.4 0 / 0 +0.0 0 +0.0 +0.32 +29.0
3ARI 27 +0.770 +0.849 -0.079 +20.8 0 / 0 +0.0 0 +0.0 +0.49 -4.9
4DEN 29 +0.383 +0.279 +0.103 +11.1 0 / 0 +0.0 0 +0.0 +0.30 -0.4
5SEA 33 +0.040 -0.061 +0.101 +1.3 1 / 0 -5.1 3 -5.6 +0.06 +5.4
6WAS 31 +0.027 +0.118 -0.092 +0.8 0 / 0 +0.0 2 -2.8 +0.06 +7.2
7ATL 41 +0.078 +0.056 +0.022 +3.2 2 / 0 -9.7 2 -5.3 +0.10 +0.5
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 2026-10-28 11:05 UTC, from nflverse. Write-up: backtests/nfl_game_quality/FINDINGS.md.