An update on Paul DeJong’s extreme profile

Baseball is unpredictable. If someone polled the entirety of the Cardinals fan base before the year began and asked them who would lead the team in home runs this year, approximately zero people would say Paul DeJong. Somehow, even less people would have said “Paul DeJong, while playing cromulent defense at shortstop”. Nonetheless, here we stand, with DeJong hitting 15 homers in just 222 plate appearances, and looking a whole lot like the starting shortstop going forward.

You’ll have to forgive me if you’re tired of reading about him. I first warned you about Paul’s profile back on June 27th. I broke wOBA up into non-contact and on-contact portions. Non-contact plate appearances are strikeouts, unintentional walks, and hit-by-pitches. On-contact wOBA is any time fair contact is made, so balls in play and home runs. I found DeJong to have the second lowest non-contact wOBA among players with at least as many plate appearances as him. He had the third biggest difference between his on-contact wOBA and his non-contact wOBA, making him one of the most extreme hitters in the league.

Later, when looking into acquiring shortstop Zack Cozart, I noted that while his numbers have trended in the right direction, he was actually last in non-contact wOBA among those with at least as many plate appearances as himself.

Well here we are today with an update on our new favorite Cardinal. Unfortunately, he still ranks last in non-contact among those with his level of plate appearances. Here’s the bottom ten in non-contact wOBA among those with 200 plate appearances (a sample of 284 players):

It’s really hard to pull off being an above-average hitter with such bad results in terms of strikeouts and walks. DeJong’s pulled it off so far, with a 116 wRC+ entering yesterday, good for 16% above average. On-contact results take longer sample sizes than strikeouts to be reliable though, so there exists some worry that he won’t be able to keep it up.

He’s also now the most extreme hitter in the league. Here’s the current Top 10 biggest differences between on-contact wOBA and non-contact wOBA:

At this point, DeJong is in a tier on his own in terms of reliance on on-contact results. However, I would be remiss if I didn’t also point out that DeJong has improved since my first article. Here’s a breakdown of some plate discipline stats before and after I published my first take on DeJong:

The league average non-pitcher walk rate is 8.7%. DeJong has improved his walk rate since he entered the league, but it’s still a well below-average rate. He’s become a little more discerning, dropping his O-Swing% (percentage of swings at pitches out of the zone) and raising his contact rate. Those are still both below average, as the league average rates are 29.6% and 77.8% respectively.

Any improvement helps though. DeJong probably won’t ever be average in non-contact situations; what matters is if he can get it to a point where the other parts of his game makes up for it in the long-term. From June 27th on, here’s the bottom ten in non-contact wOBA:

DeJong sits in the bottom 10, but at least he’s no longer last. Still, it’s hard to be too impressed, as he still sits at an uncomfortably hard spot to actually pull off being a productive hitter, even over a good stretch for him.

Most pitches against DeJong have been either fastballs or breaking balls. Here’s a look at how he’s fared on both sides of June 27th:

DeJong is virtually the same against breaking balls, but he’s become slightly more selective against fastballs. Breaking balls will probably always give DeJong problems, but I noted in the original piece that he seemed to have quite a few issues against fastballs as well. He seems to be getting a little better.

With that in mind, here’s six strike zone heat maps, three from before June 27th, three after. The first set is all fastballs thrown to DeJong, the second is all of them he’s swung at, and the third is those that he swung and missed at:

Since his first 80 plate appearances or so, pitchers started being more careful with him, as he started seeing more fastballs to the outside portion of the plate. DeJong adjusted though, swinging at more of those pitches. In both cases, he’s been susceptible to missing pitches up in the zone.

Of course, non-contact is only part of the game. We’ll also look at where he hits his best performing batted balls.

According to Statcast, Barrels are the very best 6.7% of batted balls. Many are homers or doubles, and their average a wOBA is 1.433, more than three times the average on-contact wOBA (.370). Solid Contact is the second-best category (.692 aveage wOBA), and comprise some homers, doubles, but more fly outs than Barrels. Flares and Burners combine both bloopers and hard hit grounders, and have a high probability of being a hit. Their average wOBA is .630, right behind Solid Contact.

In terms of bad contact, there’s topped batted balls (weak grounders, .206 average wOBA), under (medium velocity fly balls and pop-ups, a .090 average wOBA), and weak contact (any batted ball under 60 MPH, .046 average wOBA) For more, check out the great Tom Tango’s work here.

That third set of heat maps hints that DeJong is part of the new breed of hitters, those that specialize in hitting the low strike, but have trouble hitting the high strike. One more set of heat maps shows this is the case. Here’s one of only DeJong’s three best types of batted balls: Barrels, Solid Contact, and Flares and Burners.

For both groups of pitches, DeJong does the most damage when the ball is low in the strike zone. If you haven’t noticed, hitting low strikes is the cool thing to do now in the majors. Ever since Dave Duncan showed that most pitchers could improve by throwing lower in the zone, pitchers have listened. Thanks to some great work from Rob Arthur of FiveThirtyEight.com , we can see that pitchers were consistently pitching lower and lower in the zone until recently:

The strike zone has been getting lower and lower since Pitch F/x debuted, as it used to grade umpires. So this isn’t all thanks to Duncan. Most of it was just pitchers taking advantage of getting more and more called strikes on low pitches. Baseball is a game of adjustments, and many hitters have re-geared their swings towards hitting the low strike a long way. Now, pitchers are starting to go back to the high fastball. That trend is only just beginning though.

Going forward, will pitchers target DeJong’s weakness up in the zone? It seems like it’s only a matter of time. Pitchers are already throwing higher in the zone in general, and there’s definitely reason to do so with DeJong specifically.

The problem is, DeJong has little margin for error. If pitchers start targeting high fastballs to DeJong more often and he can’t adjust, he’s not going to be as successful. This becomes a little more dire when looking at DeJong’s xwOBA. xwOBA is also a Statcast stat, and replaces the on-contact portion of wOBA with what each player’s batted balls should have been, based on league average production of his specific batted balls. Also, it’s more indicative of future wOBA than wOBA itself.

How does this pertain to DeJong? Well, Paul has over-performed his xwOBA thus far by .033 points. It implies that DeJong should have been more like a league average hitter thus far, rather than 16% better than average. The difference is about a win over a full season.

While a league average hitting shortstop would be fine, we’re still not sure where DeJong ultimately ends up in terms of defensive value. And we’re not sure if his current success on-contact is just a hot streak. xwOBA is more reliable than wOBA, but it too fluctuates throughout the year. DeJong is going to have his rough patches like everyone else. Add on that there’s one obvious area where pitchers could neutralize a hitter like him, and you have a lot of uncertainty in DeJong’s future.

I don’t want to sound too alarming though. It’s been fun to watch DeJong’s debut, in fact I was at his first game, when he homered in a pinch-hit appearance in a loss to the Rockies (it was an away game; I live in Denver). He jumped in right after Aledmys Diaz’s production fell off a cliff, which was helpful. It’s been extra fun for me, because I have a history of enjoying players with his extreme skill-set. Let’s see if he can continue to pull it off.