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.

Bo Nix — 2026 Every split →

Adj EPA / dropback
-0.028
Raw EPA / dropback
-0.045
Dropbacks
229
Turnover EPA
-16.2
WPA
+0.24
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1KC 32 -0.430 -0.449 +0.020 -13.7 1 / 1 -6.6 4 -6.7 -0.15 -7.8
2JAX 31 +0.345 +0.272 +0.073 +10.7 1 / 0 -4.3 0 +0.0 +0.35 +11.5
3LA 37 -0.007 -0.029 +0.022 -0.3 1 / 0 -5.3 1 -1.3 +0.15 -11.4
4SF 42 +0.092 +0.112 -0.020 +3.9 0 / 0 +0.0 0 +0.0 +0.09 -4.0
5LAC 28 -0.187 -0.233 +0.046 -5.2 0 / 0 +0.0 1 -1.3 -0.04 -0.2
6SEA 29 -0.113 -0.210 +0.097 -3.3 0 / 0 +0.0 2 -2.4 -0.12 -0.9
7ARI 30 +0.053 +0.151 -0.098 +1.6 0 / 0 +0.0 1 -1.5 -0.04 -3.0
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 2026-10-28 11:05 UTC, from nflverse. Write-up: backtests/nfl_game_quality/FINDINGS.md.