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 Darnold — 2021

Adj EPA / dropback
-0.160
Raw EPA / dropback
-0.174
Dropbacks
442
Turnover EPA
-77.1
WPA
-0.77
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1NYJ 36 -0.033 +0.080 -0.113 -1.2 0 / 0 +0.0 1 -2.9 +0.19 +10.4
2NO 40 +0.381 +0.273 +0.109 +15.3 1 / 0 -6.3 2 -3.7 +0.38 +2.8
3HOU 37 +0.236 +0.324 -0.088 +8.7 0 / 0 +0.0 3 -3.6 +0.36 -0.3
4DAL 44 +0.047 -0.036 +0.083 +2.1 2 / 0 -10.0 5 -7.2 -0.12 -0.3
5PHI 40 -0.481 -0.449 -0.032 -19.2 3 / 0 -12.6 3 -5.3 -0.52 -4.7
6MIN 46 -0.343 -0.349 +0.007 -15.8 1 / 1 -11.2 4 -9.6 -0.37 -20.3
7NYG 28 -0.394 -0.376 -0.018 -11.0 1 / 0 -3.5 3 -4.5 -0.39 -5.8
8ATL 24 -0.014 +0.055 -0.069 -0.3 0 / 0 +0.0 0 +0.0 -0.02 -13.9
9NE 34 -0.698 -0.721 +0.022 -23.7 3 / 0 -20.6 1 -2.1 -0.41 -14.5
16TB 36 -0.264 -0.320 +0.055 -9.5 0 / 0 +0.0 4 -6.3 +0.04 -14.4
17NO 33 -0.402 -0.492 +0.090 -13.3 1 / 1 -8.9 7 -12.8 -0.21 -4.7
18TB 44 -0.064 -0.124 +0.061 -2.8 1 / 0 -4.0 2 -2.6 +0.30 +1.8
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.