FIP vs. ERA

According the Fangraphs stats glossary, “Fielding Independent Pitching (FIP) measures what a player’s ERA should have looked like over a given time period, assuming that performance on balls in play and timing were league average.”

FIP adjusts for fielding luck, fielding talent, and all those things a pitcher truly can’t control. Generally speaking, FIP is a better indicator of future performance. The theory being that a pitcher whose defense has performed exceptionally well will have a lower ERA, but once that fielding performance inevitably levels off, the pitcher’s ERA may rise. The opposite is true as well. If a pitcher has a high ERA but a lower FIP, the ERA should come down as the team’s defense begins to play better.

In looking at the top-ten ERA’s for this season, I became curious which pitcher has the biggest gap.

1) Johnny Cueto: 1.89 ERA/3.45 FIP
2) Jered Weaver: 2.10 ERA/2.84 FIP
3) Justin Verlander: 2.31 ERA/2.69 FIP
4) Josh Beckett: 2.46 ERA/3.40 FIP
5) Ryan Vogelsong: 2.47 ERA/3.57 FIP
6) Tim Lincecum: 2.53 ERA/2.85 FIP
7) Roy Halladay: 2.56 ERA/2.12 FIP
8) Clayton Kershaw: 2.60 ERA/2.55 FIP
9) Cole Hamels: 2.62 ERA/2.64 FIP
10) Justin Masterson: 2.71 ERA/2.92 FIP

Now, I’ll rank the players based on their gap (FIP – ERA).

1) Roy Halladay: -0.44
2) Clayton Kershaw: -0.05
3) Cole Hamels: 0.02
4) Justin Masterson: 0.21
5) Tim Lincecum: 0.32
6) Justin Verlander: 0.38
7) Jered Weaver: 0.74
8) Josh Beckett: 0.94
9) Ryan Vogelsong: 1.10
10) Johnny Cueto: 1.56

Based in this list, it would seem Roy Halladay and Clayton Kershaw are likely pitching better than their ERA’s would suggest. It would also seem that Johnny Cueto’s ERA may not be something he can maintain beyond this season.