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UZR on FanGraphs

I’m pleased to announce that UZR (ultimate zone ratings) stats are now available on FanGraphs!

This would of course not be possible without MGL (Mitchel Lichtman), and I’m extremely grateful that he allowed us to use his fielding model. He’s put in a tremendous amount of work getting the stats ready for use on FanGraphs and I really can’t thank him enough.

Unlike other versions of UZR, the ones that appear on FanGraphs use Baseball Info Solutions location data instead of STATS location data. Also, this UZR data does not currently include outfield arms and double plays are treated as regular outs. Here are the definitions for all the UZR stats available:

DG (defensive games): The number of outs made by an average fielder at his position given the exact distribution of balls in play for that player divided by the number of outs an average player at that position makes per game.

exO (expected outs): The number of outs plus reached base errors that would be made by an average fielder given the distribution of balls in play while that fielder was on the field.

RngR (range runs): The number of runs above or below average a fielder is, determined by how the fielder is able to get to balls hit in his vicinity.

ErrR (error runs): The number of runs above or below average a fielder is, determined by the number of errors he makes as compared to an average fielder at that position given the same distribution of balls in play.

UZR (ultimate zone rating): The number of runs above or below average a fielder is in both range runs and error runs combined.

UZR/150 (ultimate zone rate per 150 games): The number of runs above or below average a fielder is, per 150 defensive games.

The UZR stats can be found in the fielding section on the player pages or in the fielding section on the leaderboards. Later this week I’ll have them integrated into the team sections. Additionally, the plan is to update these stats at least weekly during the 2009 season.

Update: The team pages now have fielding data too!