How grades work

Pull the raw numbers

Play-by-play efficiency metrics come from nflverse, tracking data from Next Gen Stats, and pass-coverage breakdowns from Pro Football Reference. Plays with win probability below 5% or above 95% are excluded before any calculation:

Stabilize with Empirical Bayes

Raw rates are shrunk toward the position mean, weighted by sample size. A season with 10 targets contributes far less signal than one with 150, preventing small-sample extremes from distorting the composite:

Compare to the field

Each stat is z-scored within its season and position group, then combined into a single composite. That composite maps to a 0–100 grade via sigmoid, where 50 is exactly average and each full z-unit shifts the grade by roughly 22 points:

grade = 100 / (1 + e^(−1.15z))