I want to say at the outset that Paul DeJong is one of my favorite Cardinals. He’s interesting to write about, and I’ve written plenty about him, but that’s not what I mean. I just honestly like rooting for him. I can’t really say why, but if I had to guess, it’s because it seems like he is just working his butt off making adjustments and figuring out how to be good at things at the major league level. Want solid defense at the most important spot in the infield? He’s on it. Need him to learn how to take a walk? Sure thing. Dodge fastballs in on the hands? I’m confident he’ll learn that too. Don’t take it lightly, then, when I say that I don’t think DeJong should be playing right now. It pains me to say it, but I just don’t think he’s healthy enough to be a major-league caliber hitter right now.
Now obviously, DeJong hasn’t said he’s hurt, so I’m operating on a little bit of guesswork here. You could almost say that DeJong has let people know he isn’t hurt, in fact. He apparently tested his grip strength and got it back to 100% before returning. He even took batting practice from Mike Matheny (???) and hit a few over the wall to reassure the then-skipper of his health. We’re going to be working in suppositions and guesswork, then, but that will have to do. Just watching DeJong, it looked to me like he had lost a bit of power. That’s a pretty broad diagnosis, though. If I’m going to make a claim like that, I better have some evidence to back it up. Well, I do!
First, let’s talk about the surface stats. That’s a good place to start, though in the 50-ish plate appearances DeJong has logged since returning it will never be definitive. He’s rocking a .050 ISO since returning, which would be third-worst of everyone in the majors with 150 PA this year. Austin Jackson, Dee Gordon, and Orlando Arcia are good company if we’re talking about defensive value- not so much when we’re talking about your power. How do you get to that low of an ISO? Well, a double as your only extra-base hit will do it. I understand that it’s a small sample, but DeJong’s slugging percentage is lower than his on-base percentage since he’s returned. Paul DeJong! The man walked roughly 0% of the time last year. Still, though. It’s 50 plate appearances. Maybe it’s just bad luck. Surely he’s had sequences like this before, right?
Okay, look, that’s not great. It’s definitely on a downward trend, and on the low end of where he’s been before. Still, though, I want more evidence before I say something’s up, and that we’re not just looking at a small sample fluke.
Batted ball stats are always a little bit iffy when it comes to the data collection, but they’re still worth looking at. In his career before his pinkie injury, DeJong hit ground balls about a third of the time and ran a hard hit rate of 37.3%. His soft contact rate was a mere 20.6%- basically, he hit the ball quite hard and didn’t put it on the ground much. Since returning from his injury, both of these skills are trending in the wrong direction. He’s up to a 42.4% ground ball rate, about 10% higher than pre-injury, and his hard hit rate has fallen to 27%. It’s not like he’s just hitting a lot more medium-hard balls, either; his rate of soft contact is up from 20.6% to 30.3%. Look, I know what you’re going to say. Small sample size! Small sample size! Here’s this fancy writer, with his graphs and his percentages, and he won’t acknowledge that he’s just cherry-picking his sample. Well, feast your eyes on this:
Hey, I hear you saying: he’s had ground ball rates higher than this, and hard hit rates lower than this, for similar stretches of games. Sure, that’s true. The power decline is immediately after he had a hand injury that was likely to sap his power, however. When you hear hoofbeats think horses, not zebras. I get it. In this case, though, we saw a ‘there might be zebras ahead’ sign before hearing hoofbeats.
With all of that said, I could still believe, only barely, that DeJong is just the victim of a terrible run of luck. Maybe he’s the victim of topping a few too many balls. Maybe some balls that used to be classified as hard hit are getting thrown into the medium bucket now. To settle things further, I went right to the source. The Statcast source data, that is. I took all the batted balls DeJong has hit in his career and bucketed them into 33-event samples. Why 33? Well, that’s the number of events since he’s returned from the DL. I wanted to look at two things. First, what has happened to the balls he absolutely used to destroy? I think of DeJong as somewhat of a guess hitter, but when he guessed right earlier this year and throughout last year, he would absolutely demolish the ball. The below graph is the number of batted balls hit over 100mph per 33 fair batted balls. It’s a moving average, so every ball is going to be in 33 samples. One quick methodological note: I didn’t take moving averages for the first 32 events of the sample, to avoid choppiness at the start of the graph. Here’s the damage:
His recent drop in hard hit balls is pretty extreme. He’s hit only three balls over 100mph since returning, when his overall career stats would suggest he should have hit eight. Even those three only barely skirted the line- a 100.5mph lineout, a 100.5mph flyout, and a 102.6mph groundball single. If you don’t think the loss in top-end power matters, I don’t know what to tell you. DeJong has built his whole game around maximizing the damage he does when he connects. The launch angle, the lofted swing, the whiffs- they’re all in service of hitting some moonshots. With that part of his game missing, it’s a lot harder to cobble together value. Paul DeJong the slap hitter is just not a very interesting major league player.
While we’re on the topic of Statcast and launch angle, I have one more rolling average chart to show you. As I mentioned above, DeJong is very much a product of the fly ball revolution. You’ve heard the catchphrases. Slug is in the air. Elevate and celebrate. Hit it high and wave goodbye. I only made up one of those! The point of the matter is that DeJong has a ton of power, and hitting the ball in the air helps him access it. Here are some career-until-injury stats to drive my point home. On line drives, popups, and fly balls, DeJong runs a wOBA of .588. That’s a tremendous rate- in the top 10% of baseball, and better than Joey Gallo so far this year. On groundballs, he’s producing only .248. Groundballs produce a lower wOBA than fly balls overall, but he’s only barely better than average there, and with his high strikeout rate he needs to do damage on contact to be a valuable contributor. So, what’s happened to his launch angle since returning?
The zebra stampede is practically overwhelming now. DeJong simply isn’t putting the ball in the air. Now, I’m not an expert on pinkie injuries. I’m not really an expert on injuries, even. You could make a solid argument that I’m not an expert on baseball. I’m pretty good at inferences, though. We’ve got a lot of measures of batting performance here. All of them are correlated to some degree, but none of them are perfectly correlated. They’re all pointing one way- the ‘something is wrong with DeJong’s power’ direction. Occam’s Razor would say to look for the simplest cause if all the causes seem equally likely, and I think that makes a lot of sense here. Maybe he’s hitting into a terrible string of batted ball luck at the same time that he is suddenly putting the ball on the ground more at the same time that he’s just randomly not crushed a few pitches for a long stretch. Maybe, though, his pinkie just hurts. You can be the judge of which is more likely.
I like to use the last section of my articles to point out potential flaws in my theses, and this one is going to be no exception. Even though we’re looking at a lot of complementary stats here, the sample is still not huge. I’m writing this during Saturday’s doubleheader, and I’ll provide an update below this paragraph, but you could maybe convince me that he’s still rusty and needs to get his timing fixed. I personally would have done that against minor league pitching, but I can understand the Cardinals’ desire to rush him back. Yairo Munoz is no one’s idea of an everyday shortstop, and DeJong is comfortably better than average when he’s right. The tough thing with pinkie injuries is that they don’t have a consistent impact on hitters. Some guys can’t adjust, and some barely seem affected. The Cardinals are obviously in a better position to know what’s going on than I am- just to list the most obvious example, I’ve never talked to Paul DeJong, whereas they have. I’m not willing to just appeal to authority here, though. I was despondent when he was initially injured because hand injuries have a way of persistently sapping power, and I thought that a low-power Paul DeJong wasn’t something I wanted to see. So far it looks like I’ve been mostly right, though I hope it’s just a sample size issue and he’s totally fine, or at the very least that he’s starting to recover already.
All the power aside, there’s one really promising part of his return. His plate discipline numbers actually look tremendous. He’s running a 10% swinging strike rate (vs. a 13% career average) while swinging at about 50% of the pitches he sees. His whiffs per swing is down to a solid 20%. To be sure, some of this could come from him trying to make more contact and thus hitting for less power. If he knows he’s hurt, this would be a sensible thing to do. Still, though, he’s kept his walks stable while cutting way down on his strikeouts. If this truly is a temporary injury situation, DeJong might come back better than ever before long. To bring this article full circle, this is what I love about DeJong. Even injured, you can see him working to become a better player. Even when the present is dark, you can imagine something bright just over the horizon. Even as I worry about 2018 Paul DeJong, I’m getting more excited about 2019.
Note: this article was written during the doubleheader on Saturday. Rather than revisit the graphs of it, I’m going to take a slightly easier way out and just write updates here. DeJong managed a double on Saturday and hit three balls over 100mph between Saturday and Sunday. He still doesn’t look quite right to me, but it’s encouraging to see him get a little more mustard on the ball. I’ll move my alarm meter from extremely alarmed to somewhat wary until we get a little more data. For what it’s worth, I’d still probably DL him to let his hand rest, but I probably would have done that two weeks ago. Living with a Munoz/Garcia platoon at short will make you do some crazy things, though, and with Wong out, I think he’s staying in the lineup for the foreseeable future.