If you’re looking for a quick summary of a player’s performance or skill set, one of the first statistics you might glance at is their Isolated Power (ISO). ISO is the difference between a player’s slugging percentage and their batting average and is their average number of extra bases per at bat. Typically, we use ISO to approximate a player’s power.

Over in the Library, we’ve updated and expanded the page on ISO, so if you’re looking to get up to speed on what ISO means and how to use it, along with a quick reference chart that tells you what a good ISO is and what a horrible ISO is, go ahead and check it out.

And as always, feel free to ask questions below in the comments section or stop by our weekly FanGraphs Q&A chat (Wednesdays at 3pm eastern). You can also find me on Twitter @NeilWeinberg44 if you have FanGraphs related inquiries during the remainder of the week.