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.

Justin Fields — 2023

Adj EPA / dropback
-0.109
Raw EPA / dropback
-0.092
Dropbacks
416
Turnover EPA
-50.4
WPA
-0.70
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1GB 42 -0.297 -0.284 -0.013 -12.5 1 / 1 -9.5 4 -9.0 -0.11 -7.8
2TB 35 -0.279 -0.246 -0.033 -9.8 2 / 0 -10.2 6 -6.9 -0.16 -10.5
3KC 25 -0.482 -0.530 +0.048 -12.0 1 / 0 -4.1 3 -5.8 -0.14 +0.2
4DEN 39 +0.167 +0.183 -0.016 +6.5 1 / 1 -10.3 4 -13.1 -0.23 +21.1
5WAS 32 +0.303 +0.360 -0.057 +9.7 0 / 0 +0.0 3 -3.0 +0.26 +1.9
6MIN 14 -0.649 -0.615 -0.035 -9.1 1 / 0 -3.9 4 -6.5 -0.25 -11.3
11DET 25 +0.115 +0.168 -0.053 +2.9 0 / 0 +0.0 2 -4.3 +0.06 +6.2
12MIN 40 -0.161 -0.140 -0.021 -6.4 0 / 1 -5.3 3 -8.5 +0.02 +7.1
14DET 37 -0.001 +0.054 -0.055 -0.1 0 / 0 +0.0 3 -3.6 +0.20 -3.4
15CLE 43 -0.265 -0.360 +0.095 -11.4 2 / 0 -1.2 3 -7.7 -0.53 -7.5
16ARI 28 -0.217 -0.129 -0.087 -6.1 1 / 0 -5.8 1 -0.5 -0.01 +2.1
17ATL 35 +0.121 +0.153 -0.032 +4.2 0 / 0 +0.0 3 -3.4 +0.23 +4.6
18GB 21 -0.071 -0.062 -0.009 -1.5 0 / 0 +0.0 5 -7.8 -0.04 +2.9
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.