What is PER? Player Efficiency Rating explained
Player Efficiency Rating in one sentence, how it squeezes a player's box score into one number, why the league average is always fifteen, and the limits you should keep in mind.
The idea in one sentence
Player Efficiency Rating, or PER, tries to sum up everything a player does in the box score into a single per-minute number. It rewards the good things — points, rebounds, assists, steals and blocks — and subtracts for the bad ones, such as missed shots and turnovers. The goal is a quick, all-in-one rating that lets you compare the statistical production of very different players at a glance.
How it is built
PER adds up a player's positive contributions, subtracts their negative ones, and adjusts the result for the pace at which their team plays, so players on fast and slow teams can be compared fairly. It is then scaled per minute and normalised across the league, and this normalisation is deliberate: it is set so that the league average is always exactly fifteen, every season. That fixed anchor is what makes the number easy to interpret.
Reading the number
Because the league average is pinned at fifteen, any PER above that is above average and anything below is beneath it. Roughly speaking, a solid starter sits in the mid-teens, an All-Star pushes into the low twenties, and only the very best players reach the mid-twenties or higher across a full season. The scale stays stable from year to year, so a PER of twenty means much the same thing in any era, which is part of its appeal.
The limits to keep in mind
PER is a useful shortcut, not the final word. It leans heavily on box-score scoring and tends to flatter high-usage players who take a lot of shots, while it struggles to capture defence, since much of good defending never shows up in the box score. A low-scoring specialist who guards the best opponent and spaces the floor can be far more valuable than their PER suggests. Treat it as a starting point, then look deeper.
Where you will see it
PER is one of the best-known all-in-one player metrics and appears throughout basketball commentary and analysis, often as a fast way to rank players or track a season. It is best used alongside pace-adjusted team ratings and defensive numbers rather than on its own. As a single snapshot of box-score production, it is handy — but the fuller picture always comes from combining it with the things it cannot see.