What this calculator does
Game score, devised by John Hollinger, condenses a box score line into one number scaled so that 10 is roughly an average game, 20 a very good one and 40 a historic performance. It weights each statistic by a rough estimate of its contribution.
The weights are what make it more than a points total. A missed field goal costs 0.7, a turnover costs a full point, and an assist is worth 0.7. A player scoring 24 on 9 of 18 shooting with 6 assists and 3 turnovers scores 19.9, which is a good night rather than a great one.
The formula
Points, plus 0.4 times field goals made, minus 0.7 times attempts, minus 0.4 times missed free throws, plus 0.7 times offensive rebounds, plus 0.3 times defensive rebounds, plus steals, plus 0.7 times assists, plus 0.7 times blocks, minus 0.4 times personal fouls, minus turnovers. The coefficients are Hollinger own and were chosen to make the scale land where it does.
| Term | Meaning |
|---|---|
| Game score | A single-number summary of an individual performance, scaled around 10 as average. |
| Negative weighting | Missed shots, fouls and turnovers all subtract, which is what separates it from a points total. |
| PER | Player efficiency rating, Hollinger season-long measure, of which game score is the single-game cousin. |
The inputs explained
| Field | What to enter |
|---|---|
| Points | Points scored. |
| Field goals made | Field goals made. |
| Field goals attempted | Field goal attempts. |
| Free throws made | Free throws made. |
| Free throws attempted | Free throw attempts. |
| Offensive rebounds | Offensive rebounds. |
| Defensive rebounds | Defensive rebounds. |
| Steals | Steals. |
| Assists | Assists. |
| Blocks | Blocks. |
| Personal fouls | Personal fouls. |
| Turnovers | Turnovers. |
When to use it
Summarising a performance
A full box score line is hard to compare against another at a glance, and game score reduces it to one figure.
Comparing two games
The scale is consistent, so a 24-point game with poor shooting and turnovers scores below a 20-point game that was efficient.
Finding standout performances
Scores above 40 are rare enough to be notable, which is how the measure is most often used in coverage.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How much do points move game score?
The same supporting line with the points total varying.
| Points | Game score | Rough guide |
|---|---|---|
| 12 | 7.9 | ~10 average game, ~20 great game, ~40 historic performance |
| 24 | 19.9 | ~10 average game, ~20 great game, ~40 historic performance |
| 40 | 35.9 | ~10 average game, ~20 great game, ~40 historic performance |
Questions
What is a good game score?
Around 10 is an average starter performance, 20 is very good, 30 is excellent and 40 or above is a historic night. The scale was deliberately set to resemble points scored, which makes it intuitive to read.
How does it differ from points scored?
It subtracts for missed shots, turnovers and fouls, and adds for rebounds, assists, steals and blocks. A high-volume scorer shooting poorly can score fewer game score points than a lower scorer who was efficient, which is the whole point.
What is the relationship to PER?
Game score is the single-game version of the thinking behind player efficiency rating. PER is calculated per minute, adjusted for pace and normalised so the league average is 15. Game score is simpler and applies to one game.
Does game score measure defence?
Barely. Steals and blocks are the only defensive inputs, and they capture a small fraction of defensive contribution. A strong defender who neither steals nor blocks is invisible to it, which is a limitation shared by most box-score metrics.
For shooting efficiency alone, see the true shooting percentage calculator. For field goal percentage adjusted for threes, see the eFG% calculator.