Career minutes-weighted Player Efficiency Rating. Relative rating normalizes each player 0–100 against the all-time leader.
PER (Player Efficiency Rating) distills a player's per-minute, pace-adjusted box-score contributions into one number, standardized so league average is always 15.
Created by John Hollinger; adds up positive contributions (points, rebounds, assists) and subtracts negatives (missed shots, turnovers).
Known blind spot: elite on-ball defenders whose impact doesn't fully show up in the box score — Bruce Bowen, Tony Allen, and Metta World Peace all rate lower on PER than their real defensive impact suggests.
Per-minute means a player logging 15 minutes a game can post the same PER as a 30-minutes-a-game starter — the model separately adjusts for games and minutes played to account for that.
PER feeds into PPP (45% weight) alongside WS/48 — see the PPP page for how the two combine into a single 0-10 grade.