About
Simplified efficiency = (PTS + REB + AST + STL + BLK) - (TOV + missed FG + missed FT). NBA avg per game ~15-25. Stars 30+. MVP-level 35+. Hollinger's full PER is more complex (pace + opponent adjusted).
Formula
About basketball efficiency (EFF)
Basketball efficiency, usually written EFF, is the NBA's official one-number box-score summary of a player's all-around production in a game. It adds up everything a player did to help the team (points, rebounds, assists, steals, blocks) and subtracts everything that hurt it (missed field goals, missed free throws, turnovers). The result is a single signed number that lets you rank a stat line at a glance without juggling eight separate columns.
The metric has been published in NBA game notes and league leaderboards for decades and is the simplest member of a family of advanced ratings that includes John Hollinger's pace-adjusted Player Efficiency Rating (PER), Win Shares, and Box Plus/Minus. EFF stays popular precisely because it needs nothing beyond a standard box score, so it works identically for the NBA, NCAA, EuroLeague, and your local rec league.
How it works: the formula
EFF is a straight sum of positive contributions minus a sum of negative ones. There are no weights or pace adjustments, which is both its strength (transparency) and its weakness (it rewards volume).
EFF = (PTS + REB + AST + STL + BLK)
- (Missed FG + Missed FT + TOV)
Missed FG = FGA - FGM Missed FT = FTA - FTM
- PTS, REB, AST, STL, BLK = points, total rebounds, assists, steals, blocks: the five positive counting stats.
- Missed FG / Missed FT = field goals and free throws attempted but not made. Each miss is a minus one.
- TOV = turnovers, also weighted at minus one because the team loses the possession.
- Per-game vs total: sum a single game for game EFF, or divide a season total by games played for per-game EFF.
Worked example
A forward posts this line: 28 points on 10-of-19 from the field and 6-of-8 at the line, 9 rebounds, 5 assists, 2 steals, 1 block, and 3 turnovers.
- Positive stats: 28 + 9 + 5 + 2 + 1 = 45.
- Missed FG: 19 attempts minus 10 made = 9.
- Missed FT: 8 attempts minus 6 made = 2.
- Negative stats: 9 + 2 + 3 turnovers = 14.
- EFF: 45 minus 14 = 31.
EFF benchmark tiers (per game)
These ranges reflect typical NBA per-game EFF. Season leaders cluster at the top; the league has only ever seen a handful of 30-plus full-season averages.
| Per-game EFF | Tier | Typical profile |
|---|---|---|
| 35+ | MVP / historic | Best player in the league for that season |
| 28 to 34 | All-Star | Franchise cornerstone, All-NBA candidate |
| 22 to 27 | Quality starter | Reliable two-way contributor, fringe All-Star |
| 15 to 21 | Solid rotation | Dependable starter or sixth man |
| 8 to 14 | Bench role | Specialist or developing player |
| Below 8 | Deep bench | Limited minutes, low usage |
Common pitfalls
- Rewarding empty volume. A high-usage scorer who shoots 38 percent can post a respectable EFF on sheer attempt count even while hurting the team's offense. Always read EFF alongside true shooting percentage.
- Ignoring minutes. EFF is a counting stat, so a starter logging 36 minutes will out-EFF a more efficient bench player in 18 minutes. To compare fairly, convert to EFF per 36 minutes or use PER.
- Treating it as a defensive metric. Only steals and blocks register. Elite on-ball defenders who never gamble for steals look invisible in EFF.
- Cross-league comparison. A 40-minute NCAA game inflates totals versus a 32-minute high-school game. Benchmark tiers only hold within the same league and pace.
- Forgetting team pace. Fast-break teams generate more possessions, more shots, and more counting stats, lifting every player's raw EFF relative to a slow, half-court team.
EFF vs other advanced metrics
EFF is the entry point, not the final word. Analysts layer several metrics because each answers a different question. Use this quick map to decide which one fits your purpose.
| Metric | What it adds over EFF | Best for |
|---|---|---|
| EFF | Nothing; raw box-score sum | Fast read of overall production |
| PER (Hollinger) | Pace and minutes adjustment, mean set to 15 | Comparing players across teams and eras |
| True Shooting % | Scoring efficiency including 3s and free throws | Judging shot quality, not volume |
| Box Plus/Minus | Per-100-possession impact vs league average | Estimating two-way value |
| Win Shares | Wins attributed to a player over a season | Season-long cumulative value |
Related tools
Frequently asked questions
What is a good basketball efficiency (EFF) number?
For a single NBA game, an EFF of 15 to 25 is a solid starter line, 25 to 30 is very good, and 30 or above is All-Star territory. Season-long per-game EFF leaders sit around 28 to 32; the all-time single-season record belongs to Nikola Jokic and Giannis Antetokounmpo in the 30+ range. A bench player typically lands between 8 and 15.
How is the simplified EFF different from Hollinger's PER?
This tool uses the NBA box-score efficiency formula: (PTS + REB + AST + STL + BLK) minus (missed FG + missed FT + turnovers). It is a raw counting stat. John Hollinger's Player Efficiency Rating (PER) takes the same building blocks but adjusts for pace, minutes played, and league average, then rescales so the league mean is exactly 15. PER is a rate stat; simplified EFF is a volume stat that rewards heavy minutes.
Why can two players with the same points have very different EFF?
EFF rewards all-around contribution and punishes inefficiency. A guard who scores 25 on 9-of-12 shooting with 8 assists and no turnovers will far outscore a guard who also gets 25 but on 10-of-26 shooting with 5 turnovers, because every missed field goal and turnover is a minus-one in the formula. Volume scoring with poor shooting can even produce a negative net contribution.
Does EFF account for defense?
Only partially, through steals and blocks. EFF cannot see contested shots, help rotations, deflections, or positioning, so elite perimeter defenders are systematically undervalued. For defense, pair EFF with Defensive Rating, Defensive Win Shares, or Defensive Box Plus/Minus, which use possession and on/off data the box score alone does not capture.
Can I use EFF for college or high-school stats?
Yes. The formula is league-agnostic because it only needs box-score counting stats, so it works for NCAA, FIBA, EuroLeague, and high-school lines. Just remember the benchmark tiers shift: a 40-minute college game inflates totals relative to a 32-minute high-school game, so compare EFF only against players in the same league and minutes context.