Slugging average

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In baseball statistics, slugging average (often abbreviated SLG or SA) is a measure of the power of a hitter. It is calculated as total bases divided by at bats.

SLG = (h + d + 2t + 3hr) / (n_{AB}), where (n_{AB}), is the number of at-bats for a given player, and h, d, t, hr, are the number of hits, doubles, triples, and home runs, respectively. The following site provides information on calculation, total bases, total official at bats, slugging, and other baseball statistics: ESPN's MLB statistics glossary.

For example, in 1920, Babe Ruth was playing his first season for the New York Yankees. In 458 at bats, he had 172 hits, 36 doubles, 9 triples, and 54 home runs, which brings the total base count to (172 × 1) + (36 × 1) + (9 × 2) + (54 × 3) = 388. He had 458 at bats, so his total number of bases (388) divided by his total at-bats (458) is .847, his slugging average. The next year he slugged .846, and for 80 years those records went unbroken until 2001, when Barry Bonds hit 411 bases in 476 at-bats, bringing his average to .863, unmatched since.

The term slugging percentage is a misnomer, as it is actually a calculation of average, not percent.

Another way of calculating

Another equivalent way of calculating a batter's slugging average is SLG = (s + 2d + 3t + 4h)/(n_{AB}),, where s, are the number of singles; so that each base touched counts as one. MLB.com and many major statistical sources often don't note the number of singles a player has hit both because they assume that the reader can quickly figure it out, and because it is somewhat insignificant data for judging a player's batting performance compared to more pertinent stats such as batting average, on base percentage, and extra base hits (or their derivative, slugging percentage). Taking any Major League Baseball player's statistics, which can be found at MLB.com's statistics website, you can calculate slugging percentage using both methods above. The numbers can then be compared to the slugging average listed on the MLB.com website. One site that uses this method is Baseball Almanac's Statistical Formulas Website, listed here to demonstrate the method by which some also correctly calculate slugging average.

Slugging average's significance

Long after it was first invented, the slugging average gained new significance when baseball analysts realized that it combined with on-base percentage to form a very good measure of a player's overall production. Allen Barra and George Ignatin were apparently the first to combine the two statistics, multiplying them together to form what is now known as "SLOB" (Slugging × On-Base). Bill James applied this principle to his Runs Created formula several years later (and perhaps independently), essentially multiplying SLOB × At-Bats (the actual formula for Runs Created is: <math>RC = [(Hits + Walks)(Total Bases)]/[At Bats + Walks]</math>). In 1984, Pete Palmer and John Thorn developed perhaps the most widespread means of combining slugging and on-base average: OPS. "OPS" simply stands for "on-base plus slugging", and is a simple addition of the two values. While less accurate than SLOB and Runs Created, OPS is extremely easy to calculate, and has become the unofficial shorthand form of player evaluation in recent years.ja:長打率 zh:長打率