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 Herbert — 2026 Every split →
Adj EPA / dropback
-0.215
Raw EPA / dropback
-0.224
Dropbacks
200
Turnover EPA
-46.3
WPA
-1.43
| Week | Opp | Dropbacks | Adj EPA/db | Raw EPA/db | Schedule | Total adj EPA | INT / FL | Turnover EPA | Sacks | Sack EPA | WPA | CPOE |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | ARI | 30 | -0.303 | -0.187 | -0.116 | -9.1 | 1 / 0 | -2.3 | 3 | -5.6 | -0.04 | -6.2 |
| 2 | LV | 30 | -0.074 | -0.019 | -0.055 | -2.2 | 2 / 0 | -7.9 | 3 | -3.3 | +0.02 | -6.3 |
| 3 | BUF | 36 | -0.171 | -0.177 | +0.005 | -6.2 | 1 / 0 | -5.8 | 2 | -2.9 | -0.20 | -1.0 |
| 4 | SEA | 35 | -0.132 | -0.229 | +0.098 | -4.6 | 2 / 1 | -13.6 | 4 | -9.7 | -0.27 | -3.9 |
| 5 | DEN | 28 | -0.282 | -0.364 | +0.083 | -7.9 | 1 / 1 | -8.7 | 5 | -12.2 | -0.66 | -6.6 |
| 6 | KC | 41 | -0.315 | -0.341 | +0.025 | -12.9 | 1 / 0 | -7.9 | 4 | -4.4 | -0.29 | -9.9 |
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 2026-10-28 11:05 UTC, from nflverse. Write-up:
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.