Aggregate Defensive Ratings

These days it’s common place to look at multiple defensive metrics to try and get a good grasp of a player’s defensive value. On FanGraphs we even carry four different defensive metrics that include Mitchel Lichtman’s UZR, Sean Smith’s Total Zone (with Location), John Dewan’s DRS, and Tangotiger’s Fan’s Scouting Report.

All of them have different methodologies and the four rely on three different data sources.

To make comparing the four easier, there is now a new stats table on the player pages called “Aggregate Defensive Ratings” (ADR), where the UZR, DRS, TZL, and FSR are given a weighted average and there’s even a standard deviation and standard error given for the sample of four defensive metrics.

The general weighting is 1/3/3/3 for FSR/UZR/TZL/DRS. For years where FSR is not available, UZR, DRS, and TZL are weighted evenly. Only players with more than 50 innings played at a position are included in ADR.

ADR stats are available in all the player pages and will be making their way to the leaderboards soon.

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David Appelman is the creator of FanGraphs.