What is Player Efficiency Rating (PER) in Basketball
Player Efficiency Rating (PER) is a per-minute basketball statistic developed by ESPN's John Hollinger that summarizes a player's total statistical contributions into a single number, normalized so the league average is always 15.
Player Efficiency Rating (PER) is a per-minute basketball statistic created by ESPN's John Hollinger that attempts to distill a player's overall statistical contribution — positive (points, rebounds, assists, steals, blocks) and negative (missed shots, turnovers, personal fouls) — into a single number. PER is pace-adjusted and normalized so that the league average is always 15.0 in any given season.
PER was one of the first widely adopted all-in-one basketball metrics and remains a common reference point in player analysis, though it has well-known limitations.
How PER Is Calculated
PER aggregates per-minute contributions using weighted values for different statistics. The formula gives positive weight to:
And negative weight to:
- Missed field goals
- Missed free throws
- Turnovers
- Personal fouls
The result is adjusted for pace (teams playing in faster-paced games produce more statistical opportunities) and then normalized to the league average of 15.
PER Rating Scale
| PER | Player Quality |
|---|---|
| 35+ | Historically exceptional (rare; reserved for all-time great seasons) |
| 25–35 | MVP-caliber player |
| 20–25 | All-Star level |
| 17.5–20 | Solid starter, above average |
| 15 | League average |
| 13–15 | Below-average starter |
| 10–13 | Backup/role player |
| Under 10 | Fringe roster player |
Michael Jordan's career PER of 27.91 is the highest in NBA history. Other career leaders include LeBron James (26.4+), Shaquille O'Neal (26.4), and David Robinson (26.2).
PER and Scoring-Heavy Players
One of PER's well-documented limitations: it rewards high-volume scorers substantially — even inefficient ones — because points go directly into the formula's positive column without fully accounting for shot quality or opportunity cost. A player who scores 25 points on 20 field goal attempts (bad efficiency) may create a higher PER than a player who scores 15 points on 12 attempts (good efficiency) because raw points are credited heavily.
Box Plus/Minus (BPM) and VORP (Value Over Replacement Player) are considered more sophisticated modern alternatives.
PER vs. Win Shares vs. BPM
| Metric | What It Measures | Limitation |
|---|---|---|
| PER | Per-minute efficiency | Overweights scoring; ignores defense largely |
| Win Shares | Cumulative contribution to wins | Advantages high-minute players |
| BPM | Per-100-possession impact, both ends | Requires larger sample sizes |
When PER Is Useful
Despite its limitations, PER is a useful quick-glance metric for:
- Comparing players across different eras (normalized to league average)
- Evaluating per-minute performance for players with vastly different playing time
- Getting a rough approximation of overall statistical impact
For a more complete picture, analysts recommend combining PER with defensive metrics and team context. PER tells you a great deal about a player's offensive and rebounding contribution but is notably weak at capturing defensive impact.
It remains one of the most referenced statistics in NBA discussions and appears frequently in Hall of Fame arguments, trade deadline debates, and MVP voting conversations.