Sports Reference Blog

Fielding Independent Pitching (FIP) added to

Posted by sean on April 17, 2014

Last night, I added FIP (short for Fielding Independent Pitching) to the site. This is a sabermetric stat for pitchers that approximates ERA without the effect of their team's fielding ability. FIP actually correlates to future ERA better than ERA itself making it a superior indicator of future performance.

The idea is that the pitcher most directly controls the number of walks, home runs and strikeouts that occur and that the batters and fielders have a bigger say on whether balls in play are turned into outs and that most pitchers' Batting Average on Balls in Play (BAbip) reverts to a league average from one year to the next.

FIP is (13*HR + 3*(BB+HBP) - 2*SO)/IP + Constant(year). The constant is set so the yearly avg FIP equals the yearly avg ERA.

FIP can be looked at exactly like ERA and is scaled to exactly the same league average as ERA, but it's range will be slightly smaller.

Often a player with a low FIP and high ERA will improve, while a low ERA and high FIP indicates a likely regression as more hits start falling. I've placed FIP next to ERA to make this comparison more obvious, but if it begins making the ERA lookup too hard, I may move it further right on the pitching tables.

I've also added FIP and K% to the Play Index Season Finder. Right now, I don't believe we will add xFIP given the inconsistency in batted ball data, but that could change.

Player with big gap in FIP and ERA: Ricky Nolasco.

10 Responses to “Fielding Independent Pitching (FIP) added to”

  1. mountm Says:

    There's a missing term in your definition of FIP - it's on a per-inning basis.

    FIP is calculated as [13*HR + 3*(BB+HBP) - 2*SO]/IP + Constant(year)

  2. Dr. Doom Says:

    I just noticed this this morning! I thought, "Are my eyes deceiving me?" Nice addition!

    Also, Mountm is correct in that you need IP in the denominator. But this is a very exciting addition! Kudos on helping out with something that's fun to look at, that used to require shuffling over to the Other Site. :)

  3. mountm Says:

    Yes, I should add that I'm delighted to have FIP available on BBref! I also like having it directly adjacent to ERA on the pitching tables as it makes a quick "luck" estimation visually simple.

  4. Neil Paine Says:

    Well, glory be. :)

  5. Jim Says:

    Sean...Thank you...thank you! Been waiting a long time for FIP. Will it eventually appear with the minor league pitchers stat line?

  6. Jay Says:

    Is there any way that I can elect to have a column automatically hidden from view?

  7. shoewizard Says:

    RA9+ please. :)

  8. Danny Wind Says:

    While I'm glad to have it on the site, I would vote for it to be moved away from ERA on the pitching tables--it's too easy to get confused about which column you're looking at.

  9. Tim Pea Says:

    This came up at the Cedar Rapids city council meeting last week.

  10. DavidJ Says:

    I agree with Danny Wind about moving it away from ERA on the player page. A logical place would be next to the HR/9, BB/9, and SO/9 columns, wouldn't it?

    And I agree with Shoewizard too (though I'd rather see it as RA9-).

    Anyway, glad to finally see FIP on the site!