Isolated power

 ( Batting Statistics ) 

In baseball, isolated power or ISO is a sabermetrics computation used to measure a batter's raw power. One formula is slugging percentage minus batting average.

$ISO\; =\; SLG\; -\; AVG$

$=\; \backslash frac\{\backslash mathit\{TB\}\; -\; H\}\{AB\}$

$=\; \backslash frac\{(\backslash mathit\{1B\})\; +\; (2\; \backslash times\; \backslash mathit\{2B\})\; +\; (3\; \backslash times\; \backslash mathit\{3B\})\; +\; (4\; \backslash times\; \backslash mathit\{HR\})\}\{AB\}\; -\; \backslash frac\{H\}\{AB\}$

$=\; \backslash frac\{(\backslash mathit\{1B\})\; +\; (2\; \backslash times\; \backslash mathit\{2B\})\; +\; (3\; \backslash times\; \backslash mathit\{3B\})\; +\; (4\; \backslash times\; \backslash mathit\{HR\})\; -\; (\backslash mathit\{1B\}\; +\; \backslash mathit\{2B\}\; +\; \backslash mathit\{3B\}\; +\; \backslash mathit\{HR\})\}\{AB\}$

$=\; \backslash frac\{(\backslash mathit\{2B\})\; +\; (2\; \backslash times\; \backslash mathit\{3B\})\; +\; (3\; \backslash times\; \backslash mathit\{HR\})\}\{AB\}$

The final result measures how many Extra-base hit a player averages per at bat. A player who hits only singles would thus have an ISO of 0. The maximum ISO is 3.000, and can only be attained by hitting a home run in every at-bat.

The term "isolated power" was coined by Bill James, but the concept dates back to Branch Rickey and his statistician Allan Roth.

• PECOTA

• Baseball Prospectus Glossary
• Baseball Simple : Isolated Power (ISO) Calculator
• FanGraphs Sabermetrics Library