# Slugging percentage

(Redirected from Slugging Percentage)
Babe Ruth holds the MLB career slugging percentage record (.690).[1]

In baseball statistics, slugging percentage (SLG) is a measure of the batting productivity of a hitter. It is calculated as total bases divided by at bats, through the following formula, where AB is the number of at-bats for a given player, and 1B, 2B, 3B, and HR are the number of singles, doubles, triples, and home runs, respectively:

${\displaystyle \mathrm {SLG} ={\frac {({\mathit {1B}})+(2\times {\mathit {2B}})+(3\times {\mathit {3B}})+(4\times {\mathit {HR}})}{AB}}}$

Unlike batting average, slugging percentage gives more weight to extra-base hits such as doubles and home runs, relative to singles. Walks are specifically excluded from this calculation, as a plate appearance that ends in a walk is not counted as an at bat.

The name is a misnomer, as the statistic is not a percentage but a scale of measure whose computed value is a rational number in the interval [0, 4]. A slugging percentage is always expressed as a decimal to three decimal places, and is generally spoken as if multiplied by 1000 (so a slugging percentage of .589 would be spoken as "five eighty nine").

In 2016, the mean average SLG among all batters in Major League Baseball was .417.[2]

## Example calculation

For example, in 1920, Babe Ruth played his first season for the New York Yankees. In 458 at bats, Ruth had 172 hits, comprising 73 singles, 36 doubles, 9 triples, and 54 home runs, which brings the total base count to (73 × 1) + (36 × 2) + (9 × 3) + (54 × 4) = 388. His total number of bases (388) divided by his total at-bats (458) is .847, his slugging percentage for the season, setting a record that stood until 2001, when Barry Bonds achieved 411 bases in 476 at-bats, bringing his slugging percentage to .863, unmatched since.[3]

## Significance

Long after it was first invented, slugging percentage gained new significance when baseball analysts realized that it combined with on-base percentage (OBP) to form a very good measure of a player's overall offensive production (in fact, OBP + SLG was originally referred to as "production" by baseball writer and statistician Bill James). A predecessor metric was developed by Branch Rickey in 1954. Rickey, in Life magazine, suggested that combining OBP with what he called "extra base power" (EBP) would give a better indicator of player performance than typical Triple Crown stats. EBP was a predecessor to slugging percentage.[4]

Allen Barra and George Ignatin were early adopters in combining the two modern-day statistics, multiplying them together to form what is now known as "SLOB" (Slugging × On-Base).[5] Bill James applied this principle to his runs created formula several years later (and perhaps independently), essentially multiplying SLOB × At-Bats to create the formula:

${\displaystyle {\text{RC}}={\frac {({\text{hits}}+{\text{walks}})\times ({\text{total bases}})}{({\text{at-bats}})+({\text{walks}})}}}$

In 1984, Pete Palmer and John Thorn developed perhaps the most widespread means of combining slugging and on-base percentage: OPS. "OPS" simply stands for "on-base plus slugging", and is a simple addition of the two values. Because it is easy to calculate, OPS has been used with increased frequency in recent years as a shorthand form to evaluate contributions as a batter.

## Perfect slugging percentage

The maximum numerically possible slugging percentage is 4.000. A number of MLB players (117 through the end of the 2016 season) have momentarily had a 4.000 career slugging percentage by homering in their first major league at-bat.

No player has ever retired with a 4.000 slugging percentage, but four players tripled in their only MLB at-bat and therefore share the record of a career slugging percentage of 3.000 (when evaluated without regard to a minimum number of games played or plate appearances). The players are Eric Cammack (2000 Mets), Scott Munninghoff (1980 Phillies), Eduardo Rodríguez (1973 Brewers), and Charlie Lindstrom (1958 White Sox).[6]