Paul DeJong is mostly fine...I think

In the first month or so of the season, Paul DeJong slugged 7 homers and finished April with a .275/.327/.539 batting line. Sure, he had walked 6 times and struck out 37 but his batting line – lots of homers, lots of K’s, not many walks – looked a lot like last year’s when he was a 3 win player in about ¾ of the season. It looked like he was settling in as a solid regular with a lot of power but also as a guy that you’d have to accept a lot of whiffs with as well. But then May didn’t start off so well -- .229/.393/.333 – and then on May 17 he was hit in the hand by a pitch. The pitch broke his hand and he missed about the next 6 weeks of action. He hasn’t seemed right since. In July, he batted .217/.264/.325.

Paulie. Buddy. Pal. A .589 OPS isn’t going to get it done.

A few days ago, after watching him ground out to 3rd yet again, I tweeted out that DeJong was an absolute mess. (Sorry, I looked for the tweet but couldn’t find it. You don’t want me to be the guy whose job it is to look through some Cub’s player’s old tweets to find his racist and homophobic screeds.) I decided to try and figure out what was going on with DeJong. My first step was to head straight to baseball savant.

With splits so dramatic – destroying the ball (granted, with a lot of whiffs) in one month followed by 2 months of slugging in the low-300’s – I expected to find something noticeable in terms of his exit velocity or his xwOBA.

The first thing that should stand out is that in May, when DeJong was actually batting just .229 and slugging just .333, he was actually hitting the ball like one of the best sluggers in the league. He was seriously underperforming his peripherals with an xwOBA 65 points greater than his actual wOBA. His walks were way up. Unbelievably, his strikeout rate was way down and his average exit velocity was 92 mph. That’s a hero, even though the numbers didn’t really look like it. And then he got hurt.

When he returned, his strikeouts continued to fall, but his average exit velocity did, too. He wasn’t making as much hard contact, but he was making more consistent contact and, again, seriously underperformed his peripherals. Even though his actual OPS was below .600, it should have been much closer to his April OPS simply because he was putting the ball in play a lot more often. His ISO was .264 in April and .104 and .108 in May and July, respectively. With the walk rate up and the K rate down, is this the Paul DeJong we should expect going forward?

It's obviously good news if DeJong’s improving his ability to put the ball in play by reducing his strikeouts but it’s problematic if he’s going to be slugging like Billy Hamilton in order to do it. Some of it can probably be attributed to the hand injury. There are probably some lingering effects that reduces his ability to hit for power but if we take a deeper look into the numbers, I’m not entirely sure that’s the case.

DeJong’s numbers were down in both May (pre-injury) and July (post-injury), though obviously worse in July than May. In both months, his expected results were much better than his actual results. In other words, he was actually hitting the ball much better than the low OPS-es indicated. The most obvious reason for this “underperformance” was the glaring difference between his wOBA and his xwOBA on fastballs. In May, his xwOBA on fastballs was a blistering .403 and his actual wOBA on fastballs was .281. In July, we see the same thing. His xwOBA on fastballs was .395 and his actual wOBA was .268. In both months, his performance on fastballs was 70% of his total offensive production. He was terrible on offspeed pitches in July (xwOBA -- .071; actual wOBA -- .088) but those only accounted for 10% of his performance. Bottom line – he sucked on offspeed pitches but it really didn’t matter that much. I also question whether lingering effects from a broken hand can cause such a poor performance on offspeed pitches only. It sure didn’t look like the hand was affecting him very much on fastballs.

So what can account for his actual wOBA on fastballs (70% of his results) being 122 points lower than expected in May (before the injury) and 127 points lower than expected in July (after the injury)? He’s putting fastballs in play and hitting them hard both pre-injury and post-injury. In April, when he slugged .539 with a .264 ISO his xwOBA on fastballs was just .322. He creamed breaking pitches in April and then, when he started creaming fastballs in May, he didn’t get the results he should have.

Interestingly, in April he only saw 61.5% fastballs. Pitchers were throwing him breaking pitches and he mashed them. Beginning in May, he’s been getting a lot more fastballs but, as we’ve seen, the results haven’t been there. But it isn’t because he hasn’t hit them well. Just for reference, his exit velocity on fastballs in both May and July is higher than his exit velocity on breaking pitches in April. In other words, he’s been hitting fastballs harder in May and July than he hit breaking balls in April when he had a .515 wOBA on breaking pitches. The launch angles have averaged 18 and 20 percent in those 2 months. It really just seems as though the balls flying off DeJong’s bat in both May and July have found a lot of gloves. It’s just randomness – bad results. Sometimes baseball just happens.

Now, DeJong hasn’t started off so well in August but, as we’ve played just 4 games, I’m hesitant to draw any conclusions. He’s 2-7 on fastballs with a .329 xwOBA and a .355 actual wOBA so maybe the cards are starting to fall in his favor. The problem in August is that his whiff rate on breaking pitches (again, very small sample, just 9 plate appearances) is 50%. It’s quite likely that he’s frustrated by some slow months and he’s pressing some.

I don’t want to discount the notion that the hand injury may still be affecting him some but I am skeptical considering the way in which he hit fastballs in July. If we just look at all pitches in July, DeJong’s xwOBA was .342. Yadier Molina, who has a batting line right now of .288/.330/.472, has a season wOBA of .342. In other words, DeJong hit the ball in July basically like Molina did but his results turned out to be more like Francisco Peña's.

One of the biggest storylines of the Cardinals’ season this year has been the performance of Matt Carpenter. As we all know, he was one of the worst hitters in baseball for the first 6 weeks of the season. He went to Mabry and Mozeliak to get help, to find out what he needed to do better, and basically everyone told him that his results weren’t matching his expected performance. He was doing everything right and the ball just wasn’t bouncing the way we should expect. Hopefully, there would be regression to the mean and the results would turn around. And they did. And now Carp is a legitimate MVP candidate.

This story is one we should keep in mind as a guide to Paul DeJong. Why is he in the lineup every day? Why is he batting 3rd? Is Shildt an idiot? The answer appears to be the same as the answer to Carp’s questions back in May and there’s every reason to expect that, if he keeps doing what he’s doing, the results will turn around for him as well. Stop pressing and just play ball. I truly believe DeJong will be just fine.

Thanks to baseball-reference and baseballsavant for their numbers.

Thanks to you all for reading and for your patience with DeJong.