The slugging percentage is a statistic that allows you to estimate the offensive skills of a baseball player. Although batting averages consider a home run on par with first base (single) conquest, this statistic takes into account the number of bases hit instead. Despite the name, this value does not represent a percentage, but an average. A player with a high percentage of slugging has won more bases per bat.
Summary of Formulas
- Slugging Percentage (SLG) = Number of bases conquered ÷ Batting turns.
- Total bases = First Base Conquests or Singles + (2 x Second Base Conquests or Doubles) + (3 x Third Base Conquests or Triples) + (4 x Home runs).
- Total bases (alternative method) = Valid serves + Second Base or Doubles wins + (2 x Third base wins or Triples) + (3 x Home runs).
Steps
Method 1 of 3: Calculate the Slugging Percentage
Step 1. Understand the slugging rate
This value is expressed with the abbreviations SA or SLG and represents the average amount of bases won by a player in a bat. If a player reaches the (unrealistic) SLG value of 1, it means that he always wins first base at each turn to serve.
This statistic takes into account only the number of bases obtained with a valid serve and not those won as a runner or awarded for being hit by the ball. By excluding from the calculation all bases that are beyond the batter's control, a more accurate measurement of his offensive power can be obtained
Step 2. Find the number of valid beats that led to a single
Most of a player's stats do not consider this value, but it is not difficult to derive from other data. First, add the number of home runs with the number of triples and doubles to find the number of valid bars that did not lead to first base. Next, subtract the result from the player's number of valid beats to find the ones that resulted in a single.
For example, Willie McCovey's career stats show 521 home runs, 46 triples, and 353 doubles, which add up to 920. Subtract 920 from the number of valid beats made, 2211, and get the number of first bases won: 1291
Step 3. Calculate the number of bases
Add up all valid beats using this formula: First Base or Singles Conquests + (2 x Second Base Conquests or Doubles) + (3 x Third Base Conquests or Triples) + (4 x Home runs).
Willie McCovey got a total number of bases equal to: (1291) + (2 x 353) + (3 x 46) + (4 x 521) = 1291 + 706 + 138 + 2084 = 4219
Step 4. Divide the total by the number of batting turns
The resulting value corresponds to the percentage of slugging.
Willie McCovey has batted 8197 times, so his slugging percentage is 4219 ÷ 8197 = 0.5147 (rounded to 0.515). On average, he has won just over a base for every two batting rounds
Method 2 of 3: Alternative Calculation
Step 1. Find the total number of bases with a faster method
The one described above is the simplest to understand, but it requires a few more mathematical steps to find the first bases conquered. A different technique for skipping this step and finding the number of bases using the number of valid beats is explained below: Valid beats + Second base wins or Doubles + (2 x Third base wins or Triples) + (3 x Home runs).
This calculation works because, considering a base for each valid measure, all singles are included. Since you also get a single for each double, you only need to add one base for each double rolled to find the total. For the same criterion, you need to add two bases for each triple and three more bases for each home run
Step 2. Divide the result by the number of batting turns
Just as described above, the slugging percentage is equal to the number of bases divided by the number of batting turns.
Method 3 of 3: Related Formulas
Step 1. Add the percentage of slugging to the percentage of arrivals in base (OBP)
The resulting sum (a statistical value denoted by the abbreviation OPS, "On base plus slugging") takes into account the most important attack statistics. Baseball statisticians believe this value is not accurate, but it allows you to compare a player's offensive power quickly and easily.
The OPS + data is a less used value that is adapted to the championship and the stadium in which it is played. The formula for calculating it varies every year, to ensure that the championship average is equal to 100
Step 2. Calculate the adjusted slugging percentage based on the league
This statistical value was invented by the Total Baseball encyclopedia of baseball and is rarely used elsewhere. It is the most accurate way to compare the performances of different players of different years, but it is not easy to obtain the statistics you need to proceed with the calculations:
- Performance Modified (APRO) = (Percent of Finishers by Championship (OBP) / OBP of Championship) + (Slugging Percentage / Slugging Percentage by Championship) - 1.
- League stats are the average results of all players in a given year.
- Statistics are sometimes recalculated taking into account the variable of the various stadiums in which it is played.
Advice
- Just like many baseball statistics, the slugging percentage is also expressed without the decimal point. An SLG value of 300 means an average of 0, 300 bases per beat and not three hundred!
- The batting turns considered do not include all of a player's pot appearances, but only those in which he makes an attempt to win a base. A player's slugging percentage does not change if he wins a base with a walk or a bunt.
