If you’re looking for detailed information about how to calculate, interpret, and use the park and league adjusted version of your favorite pitching statistic, the FanGraphs Library now includes an expanded section on ERA-, FIP, and xFIP-.

Making park and league adjustments are central to a lot of analysis because you want to isolate the factors within a player’s control and compare them to the other pitchers of their era. ERA-/FIP-/xFIP- allow you to do just that. The procedure outlined in the entry will also to allow you to create your own “minus” stat for any possible ERA-type statistic you want, so if you’re working on your own or really like SIERA or tERA or something else, this will provide you with the tools you need.

If you have questions, feel free to comment below, find me on Twitter @NeilWeinberg44, or attend our weekly FanGraphs Q&A chats (Wednesdays at 3pm eastern).