There was quite a bit of hype, some of it substantiated and some of it a bit overdone, around several units on the St. Louis Cardinals entering the 2021 season. The corner infield duo of Nolan Arenado and Paul Goldschmidt were to fortify the team’s offense and defense by themselves. The starting rotation had a solid mix of young stars (Jack Flaherty), surprise risers (Kwang Hyun Kim), and reliable veterans (Adam Wainwright). The bullpen had a strong core, and one with Alex Reyes looking to assert himself in a new role. So it has come as a bit of a surprise that arguably the most inspiring unit on the Cardinals in 2021 has been the outfield.

I will freely admit my pessimism about the outfield situation entering the season, and with a bit more depth, the group’s overall production might be a bit more robust (which is perhaps a bit too saccharine of a way to phrase “might have a bit less Justin Williams and Lane Thomas). But the top-end players, particularly if Matt Carpenter remains a viable alternative at second base and thus freeing Tommy Edman to occasionally moonlight in right field, have produced. Harrison Bader has battled injuries on multiple occasions in 2021, but he has been his typical self when healthy–elite defense in center field with good enough offense at the plate (though his 83 wRC+ should seemingly be a bit higher; his .211 batting average on balls in play does not compute given his tremendous speed). Dylan Carlson has been a welcome surprise in center field; his batting line, 13% above league-average, complies with his prospect hype, though his ability to even play in the middle of the outfield was not a certainty when he came to St. Louis (admittedly, Carlson’s defensive metrics have been shotty, but they are lacking enough that I am not ready to jump to a conclusion on whether he’s a good center fielder, merely that he can find his way into the lineup).

But the real story has been Tyler O’Neill. For an organization that seemed to be producing potent outfielders for every team in baseball other than its own, O’Neill was perpetually toolsy and moderately productive, particularly in the field and on the bases, but never quite as dangerous at the plate as it seemed like he should have been. He had power, sure, but he struck out constantly and didn’t walk very much. O’Neill has consistently been, to use a phrase Ben Clemens used to describe him on FanGraphs which he did not invent but which I would surely be remiss not to mention, a two-true-outcome king.

In 160 plate appearances in 2021, Tyler O’Neill is fundamentally who he always was. He walks in just 3.1% of plate appearances and his strikeout rate is nearly eleven times higher than that, at 33.8%. And he is also hitting home runs. A lot of them. Despite an IL stint, his 15 home runs in 2021 are good for fourth in the National League; the next-highest ranking player in the National League with as many or fewer plate appearances than O’Neill has eight. By the measurements of both FanGraphs and Baseball Reference, Tyler O’Neill has been the most valuable player on the Cardinals this season.

There are a few ways in which O’Neill’s performance is, on the surface, not replicable. And that is not even necessarily particularly insulting to O’Neill–it is probably reasonable to assume that any given player is not going to be more productive, by wRC+, than Stan Musial was throughout his career, nor that somebody whose starting status in a seemingly mediocre outfield a few months ago was questioned would be expected to have the strongest season by a Cardinals hitter since 2010. While expecting the speedy, hard-hitting Tyler O’Neill to have a somewhat high batting average on balls in play would be reasonable, his current mark of .349 would put him in the 90th percentile of full seasons over the previous decade and it exceeds his career marks. And his 40.5% home run to fly ball rate, as much as I would like to chalk that up to his power just being so overwhelming (which, to be clear, he is absolutely destroying baseballs at the moment), would be higher than any qualified mark from the 2010s.

But in referring to my favorite quick-look statistic for whether a player’s results match how well he is making contact with the ball, xwOBA, the implication is that Tyler O’Neill has been, in reality, ever-so-slightly unlucky. O’Neill has a .408 wOBA and a .410 xwOBA, each the highest mark on the Cardinals by a somewhat healthy margin. The second-highest expected wOBA on the Cardinals belongs to Matt Carpenter, a man whose xwOBA has been touted frequently as evidence that his awful start did not reflect his true talent (and a man whose numbers for the last month or so have indeed been considerably better), but in the case of Carpenter, a slow-footed lefty with a pronounced pull tendency, it is easier to explain why his actual numbers don’t reflect how hard he is hitting the ball–just declare he’s hitting into the shift and call it a day. But for a fleet-footed right-handed batter like O’Neill, xwOBA is more salient. And he has been one of the dozen best hitters in baseball this season by it.

The underlying numbers suggest that Tyler O’Neill should be a high-BABIP player and they suggest that, despite his atrocious plate discipline numbers, he should be a productive MLB player. And perhaps there is something in O’Neill’s plate approach that makes his discipline just kind of come with the territory. He swings a lot and he swings violently and, when he isn’t hitting home runs, even beyond his statistics, he is aesthetically unwatchable. But when he is hitting home runs, he’s a premium hitter. In addition, he’s among the team’s fastest players and is a defending Gold Glove winner in left field. The Cardinals really haven’t seen a player quite like Tyler O’Neill. Well, at least not playing for the Cardinals.

Tyler O’Neill is the Javier Báez of the St. Louis Cardinals.

Javier Báez may be a frustrating comp for Cardinals fans who have spent the better part of the last decade annoyed at Báez, a player whom I would acknowledge is largely overrated. Javier Báez, the Chicago Cubs’ shortstop who has been a vital part of the team’s roster since 2016, has been praised for his ability to tag base runners and for his ability to, um, trick Will Craig into forgetting the rules of baseball? I can maybe be talked into the former, but giving Javier Báez credit for the Pittsburgh Pirates not understanding the basic rules of baseball seems generous if you’ve watched the Pirates play baseball lately. But also, I root for Javier Báez’s team’s biggest rival, so I am predisposed to questioning him. The fact of the matter is he’s a very good player, despite a career walk rate of 4.6% and a career strikeout rate of 29%. Since becoming a regular starter for the Cubs in 2018, Báez has been a top-25 position player in baseball. He is a player who finished in second in MVP voting with a 4.5% walk and a 25.9% strikeout rate; Javier Báez proves that this profile, while weird and occasionally frustrating (you will find no shortage of Cubs fans on the internet who can’t stand Báez, though he also isn’t exactly hurting for fans), can work if you provide power, speed, and defense.

Tyler O’Neill is a five-tool player in the sense that, for some reason, batting eye is not regarded as a tool by the classical definition. But he is not a well-rounded player. And that’s fine. O’Neill’s inability to draw walks will likely be a deterrent from him becoming a superstar in a Mike Trout, Mookie Betts, or Ronald Acuña Jr. vein, but if he can maintain his current level of performance, which the underlying numbers suggest he can, he can certainly go on a long, productive, and breathtaking MLB career.