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 — 2023

Adj EPA / dropback
+0.006
Raw EPA / dropback
-0.003
Dropbacks
51
Turnover EPA
-4.9
WPA
-0.26
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
5DAL 1 -1.008 -1.056 +0.047 -1.0 0 / 0 +0.0 0 +0.0 -0.00 +11.1
10JAX 2 -1.204 -1.208 +0.005 -2.4 0 / 0 +0.0 0 +0.0 +0.00 -19.7
15ARI 3 -0.056 +0.014 -0.070 -0.2 0 / 0 +0.0 0 +0.0 -0.01 -6.0
16BAL 16 +0.027 -0.040 +0.067 +0.4 1 / 0 -3.0 2 -4.4 -0.03 -2.7
17WAS 1 -1.765 -1.709 -0.057 -1.8 0 / 0 +0.0 1 -1.7 -0.00
18LA 28 +0.186 +0.202 -0.016 +5.2 0 / 1 -1.9 3 -4.4 -0.21 +0.7
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.