Grand Slams per at Bat, also known as G-SPAB, is a baseball statistic that measures how often a batter hits a grand slam per time at bat. It is calculated similar to a hitters batting average, with hits in the numerator being replaced by grand slams.

where
| Grand Slams per at Bat | |||
|---|---|---|---|
| Player | Career Grand Slams | Career At Bats | G-SPAB |
| Lou Gehrig | 23 | 8001 | 0.002875 |
| Manny Ramirez | 20 | 7702 | 0.002597 |
| Robin Ventura | 18 | 7064 | 0.002548 |
| Dave Kingman | 16 | 6677 | 0.002396 |
| Ted Williams | 17 | 7706 | 0.002206 |
| Willie McCovey | 18 | 8197 | 0.002196 |
| Alex Rodriguez | 17 | 8015 | 0.002121 |
| Jimmie Foxx | 17 | 8137 | 0.002090 |
| Babe Ruth | 16 | 8398 | 0.001905 |
| Ken Griffey, Jr. | 16 | 9509 | 0.001683 |
| Eddie Murray | 19 | 11336 | 0.001676 |
| Hank Aaron | 16 | 12364 | 0.001294 |
Bold indicates that the player is still active
|
|