Overview
FIP (Fielding Independent Pitching) is calculated from three outcomes pitchers directly control: home runs allowed, walks (plus hit batters), and strikeouts. The formula is (13 x HR + 3 x (BB + HBP) - 2 x K) / IP + constant, where the constant aligns with league-average ERA. Unlike ERA, which is influenced by defensive quality and BABIP luck, FIP isolates true pitcher skill. Pitchers with large ERA-FIP gaps tend to regress toward their FIP the following season, making FIP valuable for performance projection.