UZR Doesn’t Suck, Addison Russell’s WAR Isn’t a Fluke

Addison Russell’s overall performance is on par with the great shortstops of the last 70 years. So says WAR, one of the latest controversial stats in baseball because it struggles to capture defensive value. But just because it’s limited doesn’t mean Addison Russell’s WAR, which has been driven largely by an elite UZR, is spurious or some sort of gilded affectation. Quite the opposite, actually.

Interpreting baseball statistics outside the context for which their creators developed them is dangerous. For example, some statistics take an extraordinary amount of time to stabilize (i.e., to consider that an outcome can truly be attributed to the player’s talent). On the other hand, numbers like contact rate and plate discipline stabilize within a month. UZR and other commonly used defensive metrics, however, are not among those.

Because of this, the knock on UZR is that it takes too long to be considered a reliable gauge of talent and/or performance. But there indeed comes a point at which we can say, “Yes, UZR accurately reflects a player’s defensive talent.” That point is roughly three baseball seasons.

So it’s not this worthless metric that it’s sometimes made out to be when conversations on its merits appear on the Twitters. We should use UZR and other defensive metrics. But when we do cite said numbers, it behooves us to interpret them with proper context. As for Russell and his 8.2 fWAR, we can say, “Since Russell’s UZR is somewhat stable, his WAR over the last three years probably reflects his overall value accurately.”

You learn in Statistics 101 that reliability isn’t the same thing as validity, so against what should UZR be validated? There is no gold standard of defensive evaluation, but the eye test is pretty good. Kevin Keirmaier is largely considered the best defensive outfielder in baseball, and his UZR/150 since 2015 proves that is indeed the case. Andrelton Simmons, who many believe to be the best defensive shortstop in baseball, has a UZR/150 that is tops in MLB. Jason Heyward? Best UZR for a right fielder in MLB history. You probably won’t be surprised to see the list of players ranked highest in terms of UZR.

The more modern defensive numbers think highly of Russell, as well. The Society for American Baseball Research (SABR) created a new metric not too long ago by combining five different methodologies — including UZR — into its calculations.

“The SABR Defensive Index draws on and aggregates two types of existing defensive metrics: those derived from batted ball location-based data and those collected from play-by-play accounts. The three metrics representing batted ball data include Defensive Runs Saved from Baseball Info Solutions, Ultimate Zone Rating developed by noted sabermetrician Mitchel Lichtman, and Runs Effectively Defended based on STATS Zone Rating and built by SABR Defensive Committee member Chris Dial. The two metrics included in the SDI originating from play-by-play data are Defensive Regression Analysis, created by committee member Michael Humphreys, and Total Zone Rating.”

Addison Russell’s SABR Defensive Index was the best among all National League shortstops last year, and that’s in spite of his limited innings.

WAR and defensive metrics catch a lot of flak, some of which is deserved. But there are times when it’s necessary to take a step back in order to understand how we can use these defensive numbers appropriately. Raising your hand and saying, “UZR is trash, it doesn’t quantify defense well,” is neither accurate nor helpful to bigger conversation. It does a darn good job, actually. We just need a lot of data.

Fortunately, Addison Russell’s service of three years permits us to consider his defensive value as a legitimate commodity. One that, when combined with a high offensive ceiling, makes him one of the most valuable players in the game.