Everyone knows how it goes: An everyday outfielder gets hurt or otherwise fails to perform. The Cardinals then plug someone into that gap, and everyone realizes that the backup is good. Then the fans beat their fists on the table, demanding that this off-the-bench outfielder produced by Cardinals Devil Magic should be out there every day.

Distantly, you can hear “Bader” chants—and his glove backs it.

It’s not difficult to see why everyone’s so keen on Bader, even without looking at his defensive numbers. Back in May, John Fleming here at St. Louis Bullpen examined Bader’s defense in early looks of him. Mark Saxon of The Athletic recently penned a piece on his skills and work ethic, a testament to the strong outfield candidate they have in him. He’s even more appealing considering their other options. The Cardinals’ splash offseason signing, left fielder Marcell Ozuna, has struggled with his arm from the outset. Back in March, there was mention of shoulder soreness, underscoring his weak throws from the outfield in spring training. Even into June, the problem has persisted. It’s a concern for everyone waiting on his “cannon of an arm” to appear; coupled with his struggles at the plate (though he has turned things around, now at a 116 wRC+), he’s been both worrisome and frustrating. Similarly, Dexter Fowler has struggled to produce, well below average with a 61 wRC+. In the outfield, he’s been more of a statistical detriment than a valuable asset. As for Tommy Pham, he’s been the Cardinals’ most reliable qualified outfielder and a solid hitter this season.

Simply put, the outfield has not dazzled by any stretch of the imagination, particularly when it comes to defense. This is where Bader provides the most value.

The first reason is becoming increasingly well-known: Bader is fast, elite by Statcast standards. At 30 feet per second, his sprint speed ranks fifth in baseball. He quietly keeps company with the likes of Billy Hamilton, Adam Engel, and Trea Turner. Among the Cardinals, he’s trailed by Tommy Pham and his 28.6 feet/sec sprint speed. Such speed helps him reach more fly balls, and in turn more fly balls in his direction can be converted to outs. First, here’s a look at the top sprint speeds in baseball:

Then, a look at Statcast’s Outs Above Average leaderboard (min. 75 opportunities):

Unsurprisingly, some of the same names appear on both: DeShields, Hamilton, Engels, and Bader. (For the sake of this discussion, we can disregard the infielders on the sprint speed list.) This metric gives us an idea of how outfielders fare when it comes to play difficulty. The expected catch percentage is how many balls hit to that fielder that the average fielder would have caught, while the actual catch percentage is how many that particular fielder caught. Of the top ten outfielders by OAA, Bader has made the most plays more than the average fielder in his opportunities. Pham is the next Cardinal on the list with one out above average, good for number 40. Because the metric factors in the difficulty of plays, we can get a fair estimation of any added value a fielder might provide.

Another measurement to use is UZR, or Ultimate Zone Rating. It’s a catch-all defensive statistic accounting for runs saved/lost through outfield throws (ARM), double plays (DPR), range (RngR), and errors (ErrR):

To break it down, Ozuna still tops the list for runs saved on outfield throws, though the caveat remains that his arm strength appears to be diminished. (It’s important to note that this isn’t a measurement of arm strength.) Bader leads in range runs with 2.7, which comes as no surprise given his speed; it’s a snapshot akin to his seven outs above average. He’s the only outfielder with a positive ErrR, and there isn’t too much sloppiness to speak of yet.

The “yet” is crucial. First, it’s important to reiterate that this is an analysis of defense this season alone, hence why the data is only from 2018. Second, Bader has seen significantly less playing time and thus has a greater skew on his numbers. Third, this dive into our outfield defense is no attempt to make sweeping assumptions—it’s merely a look at the numbers we have. For these reasons, UZR/150 is comparatively better than UZR because it scales these individual numbers to 150 defensive games. By that measure, Bader wins out with a 18.2 UZR/150, while Fowler may turn out to be an objectively awful fielder this season with a -15.9 UZR/150 (FanGraphs said it, not me). Tiny sample sizes are the best.

That brings us to the argument at hand. It isn’t that Bader is the greatest player to grace the outfield but simply that there is merit in giving him more playing time. Small sample sizes may be virtually meaningless save for that they do tell us what we’ve seen so far. Given Fowler’s performance at the plate and in the outfield this season, Bader is an appealing alternative. John made a strong case for a Fowler/Bader platoon back in May (thanks again, Fleming), and it stands that both outfielders could benefit from sharing playing time. It gives Bader more innings in right field while putting Fowler in a better position to hit. While we spent the early weeks of the season considering that Bader might just be good, it’s more fitting now to consider that he might be more valuable than our other options—and with that, we can use him accordingly.

Numbers as of June 17, 2018.