How to Calculate Slugging Percentage
Three Methods:Calculating Slugging PercentageAlternate MethodRelated Formulas
While batting average counts a home run the same as a single, slugging percentage takes into account the actual number of bases scored. Despite the name, this statistic is actually an average, not a percentage. A player with high slugging percentage has a high number of bases scored per opportunity at bat.
Formula Cheatsheet
- Slugging Percentage (SLG) = Total Bases ÷ At Bats
- Total Bases = Singles + (2 x Doubles) + (3 x Triples) + (4 x Home Runs)
- Total Bases (alternate method) = Hits + Doubles + (2 x Triples) + (3 x Home Runs)^{[1]}
Steps
Method 1 Calculating Slugging Percentage
- 1Understand slugging percentage. Also called slugging average, SA, or SLG, this is a player's average number of bases per bat.^{[2]} If a player has an (unrealistic) slugging percentage of 1, their average result was a single.
- This only measures number of bases from hits, not from walks or hit by pitch. Ignoring the bases out of the batter's control makes this a more accurate measure of offensive power.
- 2Find the number of singles. Most player stats don't include singles, but it's easy to figure out from other stats. First, add Home Runs + Triples + Doubles to get all the hits that aren't singles. Then subtract your answer from the total number of Hits to get the number of Singles.
- For example, Willie McCovey has career stats of 521 Home Runs, 46 Triples, and 353 Doubles, adding up to 920.^{[3]} Subtract 920 from his career Hits of 2211 to get the number of Singles: 1291.
- 3Calculate the number of bases. Add together (Singles) + (2 x Doubles) + (3 x Triples) + (4 x Home Runs) to get the total number of bases.
- Willie McCovey scored a total number of bases equal to (1291) + (2 x 353) + (3 x 46) + (4 x 521) = 1291 + 706 + 138 + 2084 = 4219.
- 4Divide your answer by at bats. Divide total bases by the number of at bats to get the slugging percentage.
- Willie McCovey had 8197 At Bats, so his career slugging percentage is 4219 ÷ 8197 = 0.5147 (rounded to 0.515). On average, he scored a little more than one base for every two at bats.
Method 2 Alternate Method
- 1Find the total bases with a faster method. The method above is the easiest to understand, but require extra math to find the number of singles. Here's a way to skip that step and find the total bases using Hits instead: Total Bases = Hits + Doubles + (2 x Triples) + (3 x Home Runs).
- This works because one base per Hit takes care of all the singles. Since this also awards one base for each double, you only need to add 1 more base per double to find the total. Similarly, add two extra bases for triples, and three extra for home runs.
- 2Divide by at bats. Just as before, the slugging percentage is equal to the total bases divided by at bats.
Method 3 Related Formulas
- 1Add Slugging Percentage to On Base Percentage. The result, On Base Plus Slugging (OPS), takes into account the most important offensive stats. Baseball statisticians don't consider this accurate, but it's a quick and easy way to compare offensive power.^{[4]}
- OPS+ is a less commonly used statistic that adjusts for the league and park. The formula for OPS+ changes each year to make 100 the league average.
- 2Adjust slugging percentage for league. This statistic was invented for the baseball encyclopedia Total Baseball, and is rarely used elsewhere. It's a more accurate way to compare players from different years, but it might be hard to dig up the statistics you need to calculate it:^{[5]}
- Adjusted production (APRO) = (On Base Percentage / League OBP) + (Slugging Average / League SA) - 1
- The League stats are the average stats for all players that year.
- The stats are sometimes adjusted to factor in differences between parks as well.
Tips
- At bats do not include all plate appearances, only the ones where the batter makes an attempt to score a base.^{[6]} A player's slugging percentage does not change if they get a walk or make a sacrifice play.
- Like many baseball stats, this one often shows up without a decimal point.^{[7]} An SLG of 300 means 0.300 bases per at bat, not actually three hundred!
Sources and Citations
- ↑ http://www.baseball-reference.com/bullpen/Total_bases
- ↑ http://www.baseball-reference.com/bullpen/Slugging_percentage
- ↑ http://baseballhall.org/hof/mccovey-willie
- ↑ http://www.fangraphs.com/library/offense/ops/
- ↑ http://www.baseball-almanac.com/stats.shtml
- ↑ http://www.baseball-reference.com/bullpen/At_bat
- ↑ http://www.baseball-almanac.com/stats.shtml
Article Info
Categories: Baseball