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.

Mike White — 2021

Adj EPA / dropback
+0.044
Raw EPA / dropback
+0.015
Dropbacks
137
Turnover EPA
-36.4
WPA
+0.16
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
7NE 33 +0.033 -0.006 +0.039 +1.1 2 / 0 -7.1 1 -0.1 +0.02 -6.5
8CIN 48 +0.155 +0.168 -0.012 +7.5 2 / 0 -15.1 2 -3.5 +0.20 +9.5
9IND 11 +0.595 +0.576 +0.019 +6.5 0 / 0 +0.0 0 +0.0 +0.14 -0.5
10BUF 45 -0.202 -0.271 +0.069 -9.1 4 / 0 -14.3 1 -1.4 -0.20 -11.4
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.