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.

Tyler Huntley — 2023

Adj EPA / dropback
+0.073
Raw EPA / dropback
+0.093
Dropbacks
41
Turnover EPA
+0.0
WPA
-0.17
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
7DET 1 -0.972 -0.928 -0.044 -1.0 0 / 0 +0.0 0 +0.0 -0.00 -37.2
9SEA 7 +0.690 +0.740 -0.050 +4.8 0 / 0 +0.0 0 +0.0 -0.00 +10.9
17MIA 1 +4.231 +4.226 +0.005 +4.2 0 / 0 +0.0 0 +0.0 +0.00 +62.0
18PIT 32 -0.160 -0.146 -0.014 -5.1 0 / 0 +0.0 4 -5.1 -0.17 -13.4
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.