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Basketball efficiency ratings: the formula, its variants and its blind spots
One number meant to sum up a player's game. Here is how it is calculated, why two box scores can show two different ratings for the same performance, and what the number will never tell you.
What the rating is trying to do
The efficiency rating — PIR in Europe, EFF in most American box scores — adds up what a player contributed and subtracts what he cost. The idea is old and simple: instead of reading twelve columns, you read one number.
That is its virtue, and also its limit. It shows at a glance who weighed on a game. It says nothing about on-ball defence, positioning, the screen that frees the shooter, or the smart foul with three seconds left.
The formula, in its most common form
The version used by the EuroLeague and most European competitions reads:
( Points + Rebounds + Assists + Steals
+ Blocks + Fouls drawn )
− ( Missed shots + Turnovers + Shots blocked + Fouls committed )
"Missed shots" includes two-pointers, three-pointers and free throws. That last one is the item most often forgotten when a rating is recalculated by hand.
A worked example
Take a post player with the following line:
| Statistic | Value |
|---|---|
| Two-point shots | 6 / 11 |
| Three-point shots | 0 / 1 |
| Free throws | 4 / 6 |
| Rebounds | 9 |
| Assists | 2 |
| Steals | 1 |
| Blocks | 2 |
| Turnovers | 4 |
| Fouls committed | 4 |
| Fouls drawn | 5 |
He scores 16 points (12 + 0 + 4). He misses 5 + 1 + 2 = 8 shots.
Negative: 8 + 4 + 4 = 16
Rating = 19
Why two box scores sometimes disagree
There is no single rating, but a family of formulas. The differences almost always come from the same two items.
Fouls
This is the main disagreement. Counting fouls drawn rewards a player who attacks the rim; holding fouls committed against him punishes an aggressive defender for doing his job. Some competitions and some tools therefore drop both.
The choice made in HoopSync: neither fouls committed nor fouls drawn enter the calculation. On the example above the rating goes from 19 to 18 — the player loses his 5 fouls drawn but no longer carries his 4 fouls committed. The point is to avoid punishing a hard-working defender twice: once by the bench, once by the box score.
Shots blocked
Most amateur box scores never record blocks against, simply because nobody in the stands is counting them. A rating computed without them is slightly kinder to post players. That is not an error, as long as the same rule applies to everyone all season.
Offensive and defensive rebounds
Almost every formula counts total rebounds without separating offensive from defensive, even though they are not worth the same: an offensive rebound creates an extra possession. No common formula weights it higher.
What the rating does not say
- Minutes played. A rating of 12 in 30 minutes and a rating of 12 in 9 minutes describe two very different games. Put it next to the minutes before comparing two players.
- Shot volume. The formula mechanically rewards whoever shoots a lot, as long as he makes better than one two-pointer in two. A player who takes few shots but makes them will stay behind one who takes twice as many.
- Everything that is not counted. The screen set, the defensive transition, the extra pass, the foul avoided. At youth level that is often exactly what you are trying to develop.
Using it with young players
In youth basketball the rating is a coaching tool more than a player tool. Posting a leaderboard carries a real risk: players work out very quickly which actions raise the number, and adapt their game accordingly — more shots, fewer extra passes.
- Compare a player to himself from game to game, rather than to his teammates.
- Spot a drop-off: a rating falling over three games while minutes stay flat is worth a conversation.
- Open the discussion on turnovers, which young players almost always underestimate and which the formula punishes directly.
Key points
- The rating adds contributions and subtracts costs, in a single number.
- Missed free throws count as missed shots — the most frequent omission.
- Formulas differ mainly on fouls and on shots blocked.
- Whichever variant you pick, keep it the same all season.
- Without minutes played beside it, the number misleads.
HoopSync computes the rating automatically from the box score, tracked live from your phone — including with no signal in the gym.
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