As submitted to CloserNews.com -
As you dissect your fantasy bullpen and consider possible upgrades, one often suggested metric is FIP (Fielder Independent Pitching). The formula used to calculate the value is fairly simple [(13*HR + 3*(BB+HBP - IBB) - 2*K)/IP + C] with C being a constant that averages FIP (by league and by year) at the same level as ERA. Basically, FIP takes the same number of earned runs and assigns them out based on what should have happened rather than what did happen. Take a second and wrap your mind around that.
Statistical anylses agree that FIP is useful, reporting that it is around 20% more accurate in predicting future ERA than ERA itself. Even so, the role of the relief corps on any fantasy team is to deliver in just a select few categories, with FIP being poorly predictive thereof. Most obvious of these is saves, which, like wins, has much more to do with the team around the reliever than the player himself. While it is certainly helpful to a reliever's success, a strong FIP does not directly lead to the compilation of saves. Given the huge disparity in innings pitched between starters and reliever's, the ERA category will certainly be dominated by the starters. Your relief corps will likely make a solid impact on the K category, given the penchant to put big strikeout guys at the back end. FIP takes strikeouts into account, but it is much more efficient to evaluate K/9. The only tossup is the WHIP column and, in that case, the BABIP line is a much more appropriate defense independent statistics to examine.
To tie on a pretty bow, take a gander at the FIP, but dig into other, more useful stats. Above all, do not blindly rely on FIP as a complete or dominating evaluation of relief pitchers for your team.