How is slugging percentage calculated? Slugging Percentage (SLG) Calculator: Baseball Power Guide

Welcome to this video on demystifying slugging percentage, a visual guide to baseball's premier power metric. Batting average or AVG measures how often a player gets a hit. However, it treats all hits equally, whether a single or a home run. The offensive impact is not equal.

This is where slugging percentage or SLG comes in. SLG measures a batter's power by calculating the average number of total bases earned per at bat. SLG tells you not just if they hit, but how hard they hit. The SLG formula assigns different values to each type of hit.

A single is one base, a double is two, a triple is three, and a home run is four. Total bases are calculated by summing up the bases for each hit. To find the average bases per at bat, we must define an official at bat, or AB. Walks, hit by pitches, and sacrifices are rejected, as slugging measures hitting power, not plate discipline.

Only hits, outs, and errors make it through. The calculation sequence involves five steps. Count singles, count extra base hits, calculate total bases, get total at bats, and finally, divide total bases by at bats for the SLG. Let's run the numbers with a case study.

With the raw data, we calculate 270 total bases. Dividing 270 by 500 at bats gives us a .540 SLG, which is excellent production, putting the player among the league's top power hitters. The MLB baseline for SLG is typically around .410. Scores under .350 are below average, .350 to .399 is average, .400 to .449 is good, and .450 to .549 is excellent.

.550 plus is elite power. Comparing batting average and slugging percentage, AVG focuses on the frequency of hits, treating all hits as equal to one. SLG focuses on the power of hits, scaling them from one to four. AVG favors contact hitters, while SLG favors power hitters and sluggers.

To isolate raw power, we use isolated power, or ISO. This is calculated by removing the batting average from the slugging percentage. ISO removes the quote, quote, quote, quote, quote, quote, quote, quote of singles to focus purely on extra base hitting ability. A .200 plus is excellent power, and .250 plus is elite.

The complete picture is OPS, which is on base plus slugging. Since SLG doesn't account for walks, combining it with on base percentage, or OBP, provides a comprehensive measure of overall offensive contribution. An elite complete hitter will have a 1.000 plus OPS. Historically, Babe Ruth is the career all-time leader in SLG with .690.

Ted Williams and Lou Gehrig follow. Barry Bonds holds the single-season record with .863 in 2001. Here is a Scouts cheat sheet summarizing key SLG information. Remember, walks do not count against at-bats, as SLG measures hitting power, not plate discipline.