Passer Rating vs EPA: Which Tells You More?
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Read Article →ACE Quarterback Ranking Accuracy Compared to Expectation
ACE Ranking
"Accuracy Compared to Expectation" = completions − expected completion chance, summed over every pass attempt
ACE is QuarterbackStats.com's rating for passers, built on the standard completion-percentage-over-expected idea (CPOE). Every throw has a chance of being caught, based on how far it travels, where it goes, the down and distance, pressure and the weather. Complete a hard throw and you earn a lot. Miss an easy one and you lose a lot. Add it up for the season.
Completed 35-yard throw, 35% chance+0.65
Missed 5-yard throw, 79% chance−0.79
How ACE Works
For every NFL pass attempt we estimate the chance an average passer completes that throw. The estimate comes from a logistic regression fit on every attempt in the five seasons ending with the season, using air yards (and air yards squared, so very deep throws level off), the third of the field, down, distance, field position, a hit on the quarterback, roof, cold and wind. ACE adds up completions minus those chances. ACE per 100 attempts divides by attempts so passers with different workloads compare.
The idea is the standard completion-percentage-over-expected idea (CPOE) used across football analytics. ACE is our version of it, with the model and its coefficients published on What We Track.
How to Read It
- +10 ACE: about ten more completions than an average passer would have made on the same throws.
- ACE per 100: +3 is excellent, 0 is average, −3 is well below.
- Expected completion %: low numbers mean a passer attempts hard, deep or contested throws.
The play-by-play does not mark throwaways or drops, so those count against every passer the same way. Read ACE next to EPA per dropback.
Does It Agree With Other Models?
For the top 20 quarterbacks in 2025, ACE per 100 and nflverse's own CPOE agree with a correlation of 0.92. Next Gen Stats, which uses player tracking we do not have, measured Drake Maye's 2025 completion rate at +9.1 over expected; ACE per 100 has him at +9.3.
2026 ACE Leaders
| Rk | Player | Team | Cmp-Att | xCmp% | ACE/100 | ACE |
|---|---|---|---|---|---|---|
| 1 | Joe Burrow | CIN | 135-189 | 64.2% | +7.3 | +13.7 |
| 2 | Brock Purdy | SF | 119-171 | 64.2% | +5.8 | +9.8 |
| 3 | Lamar Jackson | BAL | 68-96 | 63.4% | +9.0 | +8.4 |
| 4 | C.J. Stroud | HOU | 143-219 | 63.6% | +2.9 | +6.3 |
| 5 | Matthew Stafford | LA | 164-249 | 64.1% | +2.6 | +6.3 |
| 6 | Josh Allen | BUF | 114-171 | 63.3% | +3.4 | +5.7 |
| 7 | Geno Smith | NYJ | 122-177 | 66.1% | +3.2 | +5.7 |
| 8 | Caleb Williams | CHI | 66-91 | 66.4% | +6.1 | +5.6 |
| 9 | Jared Goff | DET | 128-191 | 64.2% | +2.8 | +5.4 |
| 10 | Trevor Lawrence | JAX | 120-184 | 63.0% | +2.6 | +4.8 |
| 11 | Jacoby Brissett | ARI | 156-234 | 65.3% | +2.0 | +4.6 |
| 12 | Dak Prescott | DAL | 163-246 | 64.5% | +1.8 | +4.3 |
| 13 | Drake Maye | NE | 117-183 | 62.1% | +1.8 | +3.4 |
| 14 | Jayden Daniels | WAS | 75-116 | 63.4% | +2.4 | +2.7 |
| 15 | Kyler Murray | MIN | 69-101 | 67.5% | +1.5 | +1.5 |
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