ISO
Description:
Isolated Power (ISO) is a measure of a hitter’s power. Or, to look at it another way, it measures how good a player is at hitting for extra bases. The formula is SLG%-BA, which removes all the singles that are included in SLG% and leaves us with a measure of just a player’s total power numbers.
Context:
2010 ISO Values

Things to Remember:
- It takes a long time for ISO numbers to have predictive power going forward: a sample size of 550 plate appearances is recommended to draw any conclusions. In other words, if Albert Pujols has a .550 ISO two weeks into the season, it’s way too early to expect that to continue.
Links for Further Reading:
Steve is the editor-in-chief of DRaysBay and the keeper of the FanGraphs Library.
You can follow him on Twitter at @steveslow.


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