Matt. Wieters.

Not so long ago, Matt Wieters was the best prospect in baseball. “Mauer with power,” they called him, and Joe Mauer is going to be in the Hall of Fame someday. Wieters played a half a season of AA in 2008 and hit .365/.460/.625. Kevin Goldstein, then in charge of scouting for Baseball Prospectus, had this to say: “A monster on offense, Wieters is a switch-hitter with plus to plus-plus power from both sides of the plate, an excellent batting eye, and a fantastic feel for contact.” Goldstein isn’t some hack- he’s currently the director of pro scouting for the Astros. That kind of prospect pedigree is great, but it’s a double-edged sword. Matt Wieters has been a solid catcher. Since he hit the big leagues in 2009, he’s accumulated the 10th-most WAR among catchers, and some of the names ahead of him, like Carlos Santana and the aforementioned Joe Mauer, are catchers in name only.

There’s absolutely nothing wrong with being a serviceable major leaguer. The thing is, though, if you were once the top prospect in all of baseball, people tend to look at that career as a disappointment. There’s nothing fair about it- Wieters is a career .251/.315/.410 hitter, good for a 93 wRC+. That’s around league average for a catcher- Salvador Perez, Kurt Suzuki, Yan Gomes, and even Russell Martin have put up somewhat comparable career lines. Heck, Wieters is a four-time All-Star, and he’s made $55 million playing baseball. Thanks to the Nationals’ penchant for deferred cash payments in their contracts, he’ll make a further $5 million in 2021 just by existing.

This prolonged, multi-paragraph introduction is just a long way of saying that the Cardinals’ new backup catcher is absolutely nothing like your average backup catcher. Francisco Pena, Tony Cruz, Eric Fryer- those are the types of backup catchers the Cardinals are used to. In the past eight years, the Cardinals have paid a backup catcher more than a million dollars exactly twice- once to Brayan Pena in an ill-fated attempt to create depth behind Molina, and once to Gerald Laird in the days before Molina became an above-average hitter. On one hand, it’s easy to see why. Even last year, when he missed a month with a *cough* personal-place injury, Molina played in 122 games and accrued 503 plate appearances, good for sixth-most among catchers. Francisco Pena managed 142 PA, third-most for a Cardinals backup since 2010 (look upon 2014-2015 Tony Cruz’s 150 and 151 PA, ye mighty, and tremble).

There are two ways to look at this. One, maybe the Cardinals simply don’t care about backup catchers. That’s hard for me to square with the way the front office handles the rest of the team, though. The Cardinals have demonstrated real skill in avoiding below-replacement-level players. Whether it’s Aledmys Diaz, Jedd Gyorko, or Yairo Munoz, the team has consistently scrounged up reasonable value throughout its lineup. Not so at catcher, where the team has somehow accumulated -2.7 WAR from non-Molina catchers since 2008. If the team isn’t aiming for this sampler platter of sub-mediocrity, what gives? Well, imagine you’re a catcher. Are you good enough to start? Maybe the thirty teams don’t think so, but you’re a major league baseball player. You’ve been one of the best athletes you’ve known as long as you’ve been alive. You were the best athlete in your neighborhood. You were the best athlete at your high school most likely. Most of your A-ball teammates washed out, but you knew you’d make it all along. Maybe your most recent team didn’t think you could make it as a starter- heck, you told your agent you wanted a place where you’d be in a time share at the very least, but he hasn’t been able to find the right opportunity just yet. Then, the Cardinals call. How’d you like to learn from one of the best, a real legend of the game, a Molina brother? You know what that means, though. Hundred, maybe hundred fifty plate appearances if you’re lucky. It’s hard to prove you’ve still got it when you’re only playing once a week. This, to me, is a far more likely outcome. To get a backup catcher with some real upside, you have to work with them, offer them a way to see themselves starting. The Cardinals haven’t been able to do that. Whatever the front office has been trying, it hasn’t worked- until now.

What is Matt Wieters going to look like as a backup catcher? Well, first of all, he’s going to look gigantic. Maybe you thought 6’2” Francisco Pena was a big catcher. Wieters is three inches taller than him. More importantly, though, Wieters is just a different class of hitter than we’ve seen backing up Molina. While the ‘with power’ part of ‘Mauer with power’ never truly panned out, Wieters has run a league-average ISO for his career. In fact, by beautiful coincidence, Wieters’ career ISO is exactly the sum of Pena’s and Cruz’s Cardinals career ISO’s. As the scouting report above mentioned, Wieters is a switch hitter, though he’s a natural righty and has historically done much more damage hitting from that side of the plate. It’s a very compact and repeatable swing, with a foot motion that looks almost like he likes the timing aspect of a leg kick but doesn’t need the power it generates:

He’s a fly ball hitter from the right side, a trend that has only accelerated over the years, and one that suits his speed- that’s not the kind of frame you want trying to beat out double plays. One downside to this swing- as I mentioned above, he doesn’t actually generate that much power. His average exit velocity on balls he hits in the air is 93.2mph, higher than league average by a smidge, but not an absolute standout number. For some Cardinals comparisons, he’s right there with Jose Martinez, Marcell Ozuna, and Aledmys Diaz, which should give you an idea of what to expect- it’s not negligible power, but he’s not Aaron Judge or anything. I have a little toy spreadsheet I use to project offensive production from power in the air and swinging-strike percentage, and righty Wieters grades out right around league average in that.

Okay, so that’s righty Wieters covered- a league-average hitter as a backup catcher. What’s not to love? Well, unfortunately, Wieters is also going to bat against right-handed pitchers. Frequently, in fact- baseball is tough like that. A natural righty, Wieters has never been as smooth or powerful from the left side. His swing is if anything lower-energy than his righty swing, with an even more token leg-lift. Here, though, there simply isn’t enough power- he’s hitting balls in the air about as frequently from the left side of the plate, but 4mph slower off his bat on average. Though the quieter swing results in more contact (he whiffs on 20.2% of his swings from the left side of the plate versus 27.6% from the right side), he just isn’t hitting the ball with enough authority to make it work. Here’s another way to put it. Since 2015 (the beginning of the Statcast era, and the earliest I have these stats), Wieters has produced a .441 xwOBA on balls hit in the air. Let’s quickly break down xwOBA here: xwOBA looks at the exit velocity and launch angle of every ball Wieters hit and works out what contact of that quality has been worth, on average, across the majors. There are some other adjustments in there, but taken broadly, you can think of it as a rough approximation of the wOBA you’d expect him to produce with the balls he’s put in play.

Now, .441 sounds pretty good to me offhand. The first number is a four! Compare that, though, to what he’s done from the right side of the plate. As a righty, Wieters has produced a .519 xwOBA when putting the ball in the air. That sounds a lot better. League average on air-balls? A cool .486. Therein lies the rub- there’s just not enough power for Wieters to be a league-average hitter from the left side. This isn’t a new thing- from 2009 to 2014 (the last year before he had surgery on his elbow), he produced a .448 wOBA on air-balls when batting as a lefty and .582 as a righty. The power differential, in other words, is nothing new. It’s only become a problem as his overall power production has declined.

What should you, as a Cardinals fan, think about Wieters at the plate? I’ve painted a pretty bland picture so far. Average hitter from one side of the plate, mediocre from the other. What’s all the fuss about? Well, think about what he’s replacing. Since 2015, Francisco Pena has recorded 57 line drives, pop-ups, and fly balls combined. He’s averaged an exit velocity of 86.1mph, worse than Wieters’ weaker side by a clean 3mph. Tony Cruz has hit 61 such balls, recording an exit velocity of 87.8mph. For completeness’ sake, Carson Kelly has 41, and an average speed of 89mph. My point is, even Wieter’s bad side is better than what the Cardinals have been getting from their catchers of late. That sinking feeling you got when Pena stepped to the plate with a man in scoring position? Well, you’ll get that feeling a lot less with Wieters.

There’s reason to believe that Wieters has further upside than I’ve described so far. In 2018, he recorded a career-high walk rate and his second-lowest strikeout rate. Per NOC+, my estimator of non-contact management, Wieters could record contact quality 13% worse than MLB average and still be a 100 wRC+ hitter. ZiPS and Steamer think he’ll run a lower walk rate and higher strikeout rate this year, but he’s demonstrated the tools to limit strikeouts and get on base via walk- he ran a career-low swinging strike rate in 2018 while making a near-career-high amount of contact. All the peripherals, in fact, line up. His out-of-zone swing rate has hit a career low, while his in-zone swing rate was still higher than his career average. It really could be true that Wieters has developed a better eye for balls and strikes in his time on the Nationals.

What’s the upshot of all of this? Why get excited about a medium-hitting catcher who might only bat 120 times this year? Well, first of all, I’m a baseball writer. It’s kind of what I do. Second of all, Matt Wieters is tremendously interesting on the merits of his stats. At various points, he has displayed all the tools. A 16.7% strikeout rate and 11.1% walk rate is serious stuff- not Joey Votto level or anything, but in the top 10-15% of all hitters in terms of non-contact stats. He’s put up 4 15-homer seasons, not too shabby for a catcher. He’s even a valuable pinch hitter against lefties, a big step up from the traditional extreme-glove-only-and-not-even-a-very-good-glove backup catchers the Cardinals have relied on in the past.

Mostly, though, I’m interested because this guy was supposed to be what Buster Posey ended up being. He was a can’t-miss prospect who was going to revolutionize the catching position, and instead turned out to be just a pretty decent baseball player. It’s fascinating to me to imagine an alternate universe, where the lightly-regarded and light-hitting Molina ended up as the journeyman and Wieters ended up as the likely Hall of Famer. In 2008, when Kevin Goldstein wrote the prospect report I quoted at the top, Yadier Molina was 26. He’d been in the majors for four and a half seasons already and only generated 5.1 WAR. He was a good defender, sure, but had never even been a league-average hitter. Ask the baseball intelligentsia in 2008, and they’d surely project Wieters as a better bet. Here we are, ten years on, and nothing is as predicted. Like so much of baseball, the Cardinals’ catching depth chart this year is more than just two adults who are adept at playing a game. It’s a meditation on the unknowability of the future, a reminder that our reality isn’t the only thing that could have occurred, or even the most likely thing to have occurred. All that philosophical nonsense aside, it’s going to be nice to have a real baseball player as a backup catcher again, too. Win-win!