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.

Patrick Mahomes — 2021

Adj EPA / dropback
+0.226
Raw EPA / dropback
+0.211
Dropbacks
818
Turnover EPA
-82.0
WPA
+4.76
WeekOpp DropbacksAdj EPA/dbRaw EPA/dbScheduleTotal adj EPA INT / FLTurnover EPASacksSack EPAWPACPOE
1CLE 39 +0.519 +0.497 +0.022 +20.3 0 / 0 +0.0 2 -2.4 +0.48 +15.9
2BAL 31 +0.558 +0.555 +0.003 +17.3 1 / 0 -3.4 0 +0.0 +0.73 +10.4
3LAC 46 +0.240 +0.241 -0.002 +11.0 2 / 0 -5.2 2 -2.6 +0.06 +1.2
4PHI 31 +0.729 +0.733 -0.005 +22.6 1 / 0 -4.0 1 -1.5 +0.53 +17.0
5BUF 56 -0.106 -0.176 +0.070 -5.9 2 / 0 -12.7 2 -1.0 -0.16 -3.6
6WAS 50 +0.247 +0.247 +0.000 +12.3 2 / 0 -9.2 3 -3.2 +0.25 +5.1
7TEN 39 -0.194 -0.174 -0.020 -7.5 1 / 0 -3.9 4 -9.5 -0.04 -5.3
8NYG 50 +0.049 +0.054 -0.005 +2.4 1 / 0 -4.7 2 -1.3 +0.06 -0.8
9GB 38 -0.218 -0.236 +0.017 -8.3 0 / 0 +0.0 1 -2.3 -0.10 -11.4
10LV 50 +0.446 +0.498 -0.052 +22.3 0 / 0 +0.0 0 +0.0 +0.55 +5.2
11DAL 40 -0.111 -0.189 +0.078 -4.4 1 / 1 -10.1 3 -8.2 -0.09 -1.9
13DEN 30 -0.081 -0.086 +0.005 -2.4 1 / 0 -4.6 1 -1.3 +0.04 -17.0
14LV 27 +0.522 +0.574 -0.052 +14.1 0 / 0 +0.0 3 -4.7 +0.14 +18.6
15LAC 48 +0.192 +0.194 -0.003 +9.2 1 / 1 -10.4 1 -4.4 +0.48 -1.0
16PIT 32 +0.561 +0.497 +0.065 +18.0 0 / 0 +0.0 2 -1.6 +0.18 +15.1
17CIN 35 +0.317 +0.324 -0.007 +11.1 0 / 0 +0.0 0 +0.0 +0.30 +12.1
18DEN 45 +0.284 +0.270 +0.015 +12.8 0 / 0 +0.0 1 -2.3 +0.26 -3.1
19PIT 42 +0.517 +0.453 +0.064 +21.7 1 / 0 -6.0 3 -5.3 +0.20 +10.6
20BUF 46 +0.549 +0.464 +0.085 +25.2 0 / 0 +0.0 2 -2.2 +1.39 +7.5
21CIN 43 -0.166 -0.148 -0.018 -7.2 2 / 0 -7.9 4 -7.1 -0.49 +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.