Slugging Percentage (SLG) Calculator
Calculate a player's batting power with this essential baseball statistic that measures the total bases per at-bat.
Understanding Slugging Percentage (SLG)
What is Slugging Percentage?
Slugging Percentage (SLG) measures a batter's power by calculating the total number of bases achieved per at-bat. Unlike batting average, SLG gives credit for extra-base hits by assigning more value to doubles, triples, and home runs.
The SLG Formula
SLG is calculated using the formula: Total Bases / At Bats. Total bases are calculated as: (1B) + (2 × 2B) + (3 × 3B) + (4 × HR), where 1B = singles, 2B = doubles, 3B = triples, and HR = home runs.
Isolated Power (ISO)
Isolated Power (ISO) is derived from slugging percentage and represents a player's raw power by removing singles from the equation. It's calculated as: SLG - BA (batting average). ISO helps differentiate between players who hit for average and those who hit for power.
Importance in Baseball Analytics
SLG is a key component in evaluating a player's offensive contribution. When combined with on-base percentage (OBP) to form OPS (On-base Plus Slugging), it creates one of baseball's most comprehensive offensive metrics. Power hitters typically have high SLG values even if their batting averages are modest.
League Averages
The MLB average SLG typically falls around .400-.430. An SLG of .500 or higher is generally considered excellent, while anything below .350 is considered poor at the major league level. Power hitters often maintain SLG values above .500 throughout their careers.
Frequently Asked Questions
How is slugging percentage different from batting average?
While batting average treats all hits equally (dividing total hits by at-bats), slugging percentage weights hits based on their total bases. A single counts as 1, a double as 2, a triple as 3, and a home run as 4. This means SLG represents the average number of bases a player achieves per at-bat, providing a better measure of power and extra-base hitting ability than batting average.
What is considered a good slugging percentage in MLB?
In MLB, slugging percentages can generally be categorized as:
- .550+ : Excellent (elite power)
- .490-.549: Great
- .450-.489: Above Average
- .400-.449: Average
- .350-.399: Below Average
- Below .350: Poor
For context, league leaders in SLG often have values around .600 or higher, while the league average typically falls between .400 and .430.
What is Isolated Power (ISO) and why is it important?
Isolated Power (ISO) is calculated by subtracting batting average from slugging percentage (SLG - BA). It essentially removes singles from the equation to focus on a player's extra-base hit production. ISO provides a clearer picture of a player's raw power by isolating their ability to hit for extra bases.
ISO values can be interpreted as:
- .250+: Elite power
- .200-.249: Great power
- .160-.199: Good power
- .140-.159: Average power
- .120-.139: Below average power
- Below .120: Limited power
Can a player have a high slugging percentage with a low batting average?
Yes, this is quite common among power hitters. A player who hits fewer singles but connects for many extra-base hits can maintain a high SLG despite a modest batting average. For example, a player might hit .240 (which is below average) but have an SLG of .500 (which is very good) if many of their hits go for extra bases. This profile is typical of power hitters who may strike out more frequently but deliver significant value through extra-base hits and home runs.
How does SLG relate to other offensive metrics?
SLG is frequently combined with other metrics to provide a more comprehensive offensive evaluation:
- OPS (On-base Plus Slugging): Combines OBP and SLG to balance getting on base with power hitting
- OPS+ (Adjusted OPS): Normalizes OPS based on league and park factors, with 100 being league average
- wOBA (Weighted On-base Average): An advanced metric that weights offensive events by their actual run value
- wRC+ (Weighted Runs Created Plus): Measures offensive value in terms of runs created relative to league average
These metrics all incorporate SLG as a key component in measuring offensive production.