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Isolated power

Sabermetric baseball statistic

Wikipedia contributorsAdapted for Fathomly · View authors
1 min read
Source updated October 9, 2023

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

ISO=SLG-AVG

={\frac {{\mathit {TB}}-H}{AB}}

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

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

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

The final result measures how many extra bases 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.

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Sources and credits

This article is adapted from the Wikipedia article “Isolated power”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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