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.

Drew Lock — 2021

Adj EPA / dropback
-0.104
Raw EPA / dropback
-0.077
Dropbacks
119
Turnover EPA
-8.2
WPA
-0.17
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
4BAL 24 -0.413 -0.393 -0.020 -9.9 1 / 0 -3.9 3 -3.5 -0.18 -8.1
12LAC 7 -0.744 -0.740 -0.003 -5.2 1 / 0 -4.3 1 +1.1 -0.10 -4.9
15CIN 13 +0.181 +0.201 -0.020 +2.4 0 / 0 +0.0 1 -0.2 +0.08 -6.3
16LV 24 -0.163 -0.094 -0.068 -3.9 0 / 0 +0.0 2 -3.4 -0.11 +2.0
17LAC 26 +0.075 +0.086 -0.011 +1.9 0 / 0 +0.0 1 -3.2 -0.03 +2.7
18KC 25 +0.093 +0.113 -0.019 +2.3 0 / 0 +0.0 1 -0.9 +0.17 -8.6
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.