Hot on the heels of Ultimate Zone Rating is another tool with the same goal: measure a player’s defensive contributions in terms of runs saved. This other statistic, Defensive Runs Saved (DRS), doesn’t just have a better name, but in my experience is favored over UZR in most situations.
The key difference between UZR and DRS is that DRS uses more specific criteria to evaluate players, and also includes specific information to evaluate catchers and pitchers. There are six components to DRS.
- Plus Minus Runs Saved – This is similar to a combination of the range and error factors from UZR.
- Home Run Saving Catch – This provides a specific boost to outfielders who “rob” a home run from going over the fence.
- Outfield Arm Runs – This is the same type of measurement as the one we saw in UZR.
- Double Play Runs – Again, similar to UZR, applying only to second basemen and shortstops.
- Bunt Runs Saved – A metric specifically for corner infielders that evaluates how they handle bunt situations.
- Stole Base Runs Saved – This is the catcher and pitcher metric; both pitchers and catchers have an impact on how frequently bases are stolen.1While this metric is not specifically used, this Foolish Baseball video does a great job elucidating the intertwined effects of catchers and pitchers in steal-prevention.
The scale of DRS is the same as that of UZR, though DRS often provides higher values than UZR due to the extra components. It is designed to be more comprehensive. Also, it only counts whole numbers of runs.
And, as you might have already guessed, these run-accumulation statistics can both be used to compute a defensive component to WAR. In fact, if you go back to the post on offensive WAR and just plug in a player’s DRS or UZR into the defensive component that we ignored, you get a total measure of position player WAR.
A Comparison
In 2015, Nolan Arenado had 22 DRS compared to Trevor Plouffe’s 0. This already is an interesting comparison between DRS and UZR. Another interesting difference is that DRS has Nolan Arenado’s 2015 as better than his 2013 (22 vs 18), while UZR has it flipped dramatically (14.6 vs. 3.1).
I suspect an aspect of this is Arenado’s absolutely phenomenal bunt defense. He’s a unique player to compare against, and in general I trust DRS’s more comprehensive view of defense.
In terms of overall WAR, from 2013 through 2015 Plouffe accumulated 6.8 WAR compared to Arenado’s 8.9. If we compare their age 27 – 29 seasons again, Plouffe’s 6.8 WAR looks even worse against Arenado’s 13.4 WAR (with the COVID-shortened 2020 season only providing 0.7 of that.)
Defensive metrics will continue to improve as we gather more data and come up with cleverer ways to compare positions. Right now, we are in a state of “good enough”, with sufficient tools to fully compare modern day players, and some tools with which we can have good conversations about players pre-2000.
Continue to Day 24 – Retrospective
- 1While this metric is not specifically used, this Foolish Baseball video does a great job elucidating the intertwined effects of catchers and pitchers in steal-prevention.