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fielding runs

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  • fielding runs

    A couple of quick questions:

    1. How are fielding runs calculated?

    2. What are the variances for fielding runs at each position?

    3. How accurate are they?

    4. Where can I get list of fielding runs for players today?

  • #2
    This is a post I made in the thread "Derek Jeter's Fielding" in the Yankees forum:

    Fielding Runs are based on the player's fielding statistics at each position compared to the league average for this number of innings played. This is the basic formula:

    PFR/(PO-SO for team)-LFR/(PO-SO for league*Player Innings

    PFR is the player fielding rate, while LFR is the league fielding rate. The rates at each position are as follows:

    P, 2B, SS, 3B: .2(PO+2A-E+DP)

    There are other factors added in to adjust for the handedness of the team's pitchers, and the amount of double play opportunites for the player.

    To adjust for the handedness of pitchers, the basic formula is multiplied by this equation:


    ADJ is the adjustmen figure appropriate for the position and statistic. No adjustment is needed for catchers or center fielders. These are the adjustment figures for each positon and stat:

    1B:n/a PO, -.4 A
    2B:.23 PO, -.27 A
    3B:-.22 PO, .34 A
    SS:-.1 PO, .14 A
    LF:-.16 PO, n/a A
    RF:.09 PO, n/a A

    YF is the year factor, necessary because this factory steadily increased in importance for 1910 to 1970. Before 1910 the YF is 0, so no adjustment is needed. The adjustment can be calculated for each year from 1910 through 1970 by subtractting 1910 from th ear in question and then dividing by 60. After 1970 the YF is always 1.

    DLHP is the difference in the precentage of left-handed pitching from the league average.

    DP opportunities were estimated from hits, BB, HBP, and HR allowed, plus errors committed. Using a multiplier for homers to account for DP opportunites lost did not improve the estimate in years where there are actual data: the average error in these years was around 2 percent. The formula for calculating DP opportunites is:


    Individual DPs were divided by the team DP opp. divided by the league average DP opp. fro catchers, there is an aditioinal defensive calculation made to rate them on other defensive aspects. I won't go into that here, though, since we're talking about a shortstop.

    I answered the question about how they are calculated, and I'll answer the others as best I can:

    2.Positions that demand more defense (SS, 2B, C, 3B) tend to have more fielding runs than the outfielders and 1B, which is to be expected. You can't really compare defensive value between different positions by using fielding runs. Since fielding runs is part of Batter Fielder Wins or TPR, that really is a good thing about it, because it gives a positional adjustment for positions from which less offense is expected.

    3.They really aren't all that accurate compared to other fielding metrics, but they are a decent metric if it's all you have access to.

    4.The 2005 ESPN Baseball Encyclopedia has fielding runs listed for every player in MLB history, and in every season.


    • #3
      Thanks for the info.

      They really aren't all that accurate compared to other fielding metrics
      So what are accurate metrics?


      • #4
        Careful...there's more than one type of Fielding Run.

        The more modern FRAA/FRAR used by BP are quite a bit different than the ones described in this thread and involve team level adjustments and so forth.

        Currently the favored fielding statistic is UZR...but that's proprietary information that can't be duplicated and hasn't been totally and completely explained beyond the theory and basic outlines.


        • #5
          UZR explained by MGL himself part 1 and part 2, it can be duplicated. One just needs:
          Retrosheet, freely available
          database software


          • #6
   canot duplicate UZR...not for all years in which it has been one but an anointed few have access to 1993-1999 PBP

            And I'm glad he's explained it more thoroughly than I had been able to find...those reports did not comeup on any net searches I attempted.


            • #7
              But you can duplicate 35 odd years of baseball, and you can duplicate his work. Which is the most important aspect. The nuts and bolts are explained and one can do duplicate his work. Whereas there are other metrics that all we see is the end result and a brief description.


              • #8
                good stuff, where can I find UZR ratings for players today?


                • #9
                  You will have to do them yourself.


                  • #10
                    Originally posted by darkplague17
                    good stuff, where can I find UZR ratings for players today?


                    • #11
                      UZR explained by MGL himself part 1 and part 2, it can be duplicated. One just needs:
                      Retrosheet, freely available
                      database software

                      Unless I am seriously missing something I don't believe the detailed zone information that MGL used to calculate UZR is available from retrosheet. He used STATS data which is not freely available.


                      • #12
                        I thought I recalled something about the zones he uses being more granular than the zones available in Retro files.


                        • #13
                          In post 57 to the discussion of his Part 1 article MGL says he uses STATS data transposed to the retrosheet format (the old project scoresheet zones). But most retrosheet scoring doesn't include even the detail from the project scoresheet zones.


                          • #14
                            Fielding Runs Above Average (FRAA)

                            Hey everyone, new to the site! I was looking at Baseball Prospectus' Fielding Runs Above Average (FRAA) statistic and looking for any unusual findings. It actually has Torii Hunter at a -5 in 2003, -2 in 2004, and 4 in 2005. They then go on to project him as having a negative FRAA in the upcoming season.

                            Just curious to how this could be? I know a lot of players get overhyped, (Bobby Abreu winning a Gold Glove, etc.), but how is he so bad? Watching him, it appears as though he has nice range and a superior ability to catch the ball. Is he really that bad? In addition, how can a player face such a large swing from year to year? Unlike hitting, I would think fielding would be unable to suffer from slumps.

                            Also, what is the consensus on the best defensive statistics out there in addition to FRAA?

                            Thanks for any help.


                            • #15
                              UZR by MGL (Lichtman), followed by PMR by Pinto (Baseball Musings), and John Dewan's Plus/Minus (Fielding Bible).

                              After that it's a chasm, and then it's all those without a PBP system, like Win Shares and BP's system among others.
                              Author of THE BOOK -- Playing The Percentages In Baseball


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