Calculate slugging percentage (SLG) from singles, doubles, triples, home runs, and at-bats to measure a hitter's raw power.
| SLG Range | Rating |
|---|---|
| .500 + | Power Hitter |
| .450 - .499 | Excellent |
| .400 - .449 | Average |
| .350 - .399 | Below Average |
| ~ .349 | Poor |
Slugging Percentage (SLG) measures the average number of total bases a hitter records per at-bat, capturing raw power. The formula is '(singles×1 + doubles×2 + triples×3 + home runs×4) ÷ at-bats'. For example, over 500 at-bats with 100 singles, 30 doubles, 5 triples, and 20 home runs, total bases equal 100+60+15+80=255, giving a SLG of 255÷500 = .510.
Batting average treats every hit equally, while slugging percentage weights doubles, triples, and home runs more heavily to reflect power. Two hitters with identical batting averages can have very different SLGs if one hits more extra-base hits, and that difference translates directly into more runs produced for the team.
A SLG of .500+ is typically considered power-hitter caliber, .450-.499 excellent, .400-.449 average, .350-.399 below average, and below .350 poor. In both KBO and MLB, a season SLG of .550 or higher is recognized as elite, league-leading power.
ISO (Isolated Power) subtracts batting average from slugging percentage to measure pure power independent of overall hit frequency. For example, a hitter with a .280 batting average and .550 SLG has an ISO of .270, meaning a very high share of their hits go for extra bases. Because SLG alone can't distinguish whether a high number comes from a high batting average or true power, ISO is often viewed alongside it.
Raising SLG starts with strength training to build bat speed and power, along with swing adjustments that optimize launch angle to increase fly-ball extra-base hits. Strengthening lower-body rotation and pull-side power on inside pitches boosts extra-base production. Good count management to avoid missing mistake pitches, combined with an aggressive approach in the zone, also contributes to a higher SLG.