Dylan Covey might be the pleasant surprise the 2018 White Sox needed

The newfound depth of the White Sox farm system is a staunch departure from the past and feels like a nice beacon of hope in a season in which the games have often been painful. The Astros, Cubs, and Indians have all shown us what can happen when a crop of such players develops together and arrives on the big stage. Still, teams like the Padres and Twins can tell you that a top farm system is no firm indicator of future success.

For that reason, I’ve been heavily interested in the major league team this season, even guys that aren’t considered a part of the future, since most competitive teams need some surprise players to break out. From the outset, the 2018 team was going to have a significant say in just how much we need to expect from the prospects and Jerry Reinsdorf’s wallet to build this team into a winner. Setting aside the subject of this post, I’d say the results so far have been mixed. The biggest positive has probably been Tim Anderson, who’s rebounding nicely from a dreadful year and looking like he could be an above-average shortstop in the future. Yoan Moncada hasn’t lit the world on fire, but he looks like a capable big leaguer right now with loud tools and plenty of potential to improve. We’ve even had a surprise player in Matt Davidson play his way back into at least a future DH consideration. No one else under long-term control has stepped up in a big way, but I’d say these are overall satisfactory results for the position players.

The pitching staff is where things were concerning early in the year. The White Sox have great starting pitching depth in the minor leagues, but you’re not going to hit on every prospect (especially pitchers) no matter how many High-A and Double-A hitters they blow away. This season, the Sox started with Lucas Giolito, Reynaldo Lopez, and Carson Fulmer in the rotation, with varying expectations. Lopez has looked like a number-four-ish starter (the advanced peripherals will have to tell me otherwise before I bump that projection up), but Giolito and Fulmer have torpedoed their stock about as hard as they could. Meanwhile, until the recent emergence of Jace Fry, none of the bullpen wild cards made a strong case for themselves. This was a troubling outcome, to say the least.

Dylan Covey is working on changing all of that. In six starts, he’s provided enough hope that Giolito’s failures are looking like something the White Sox will ultimately be able to stomach. No one should ever be penciled into the future core from six starts, especially someone with Covey’s track record of health and performance. However, Covey’s current 2.29 ERA has some thunder behind it in a way that, say, Lopez’ 2.43 ERA through six starts did not. As Steve Stone has said many times, Covey’s a different guy this year, and you can see it in virtually every aspect of the numbers.

From Brooks Baseball, here’s a look at the average velocity. Ignore the fourseam; he doesn’t really throw one. It’s the sinker velocity that’s important, as he uses it 65 percent of the time.

This corroborates what we’ve heard about Don Cooper helping Covey gain velocity by helping him follow through toward the plate rather than falling off to the side. That added heat has movement, too.

Greg Maddux would’ve put it on the corner, and Greg Maddux could do that whenever he wanted, but damn, that’s exactly who I thought of* when I watched that pitch break.

(*I do not think Dylan Covey is Greg Maddux or close to it. Please do not yell at me about this offhand observation. It would make me sad.)

Covey’s peripherals back up the added nasty factor. His FIP (2.16) is even lower than his ERA (2.29). The biggest reason is the fact that Covey hasn’t allowed a home run this season, which will obviously change at some point. Still, xFIP adjusts FIP to assume an average amount of fly balls turn into home runs, and Covey’s xFIP of 3.31 suggests that he hasn’t been extraordinarily lucky in that regard. That’s in large part due to Covey keeping the ball on the ground, as you might expect from a pitcher with a power sinker. Covey’s 61 percent ground ball rate is higher than that of every qualified starter.

I’m not the biggest fan of xFIP because it assumes all pitchers allow roughly the same profile of airborne contact, so in times like these, I like to turn to xwOBA. This metric estimates the probability of a single, double, triple, and home run based off of exit velocity and launch angle, and uses these probabilities (along with strikeouts and walks) to estimate the wOBA that a pitcher theoretically would allow given the quality of contact. Roughly .330 is league-average for xwOBA, and Covey is at .293, which puts him toward the back of the top-20 in baseball for starters with at least as many innings. His closest neighbors are Jose Berrios (.293) and Jake Arrieta (.294).

Having established that Covey’s largely earned his great results, the question turns to whether he can keep pitching this well as the league starts to pay more attention to him and a more comprehensive scouting report develops. Holding down a tough Cleveland offense after facing it about two weeks ago was a nice first step, but greater challenges are coming. One such test will be durability, as Covey’s already thrown 74 innings this year and has never topped 140 in a professional season. Another difficulty (as pointed out to me by Nick Schaefer of BP South Side) is Covey’s low swinging strike rate, which is likely a reason that Baseball Prospectus’ DRA remains skeptical despite good strikeout numbers. Should he overcome those hurdles, Covey’s given plenty of reason to hope he can become the mid-rotation starter that we’ve haven’t seen in Giolito. If he can do that, he’ll have put the future rotation’s trajectory right back on track.

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Patrick Nolan
Patrick Nolan
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This is great stuff, thanks. As a far less… erudite baseball fan I always appreciate when you guys occasionally describe what the metrics are telling us and how the inputs differ.


What’s a good innings target this season for Covey? Since he’s never cleared 140 before, do you cap him somewhere around 160? Or just let him go out there and throw as many as possible?


Is the increased velocity a risk factor? It sounds like they’re chalking it up to whole body mechanics rather than “throwing harder” but I have no idea if that makes a difference to a human elbow or shoulder.

karkovice squad

More velocity is more force. More force applied to the body is more risk of injury. Some of it can be alleviated with proper mechanics, doing the training exercises, and how they’re used/rested. Covey’s probably in good hands with the first 2 (or about as good as he can hope for). For the latter, he’s had some extended innings that might have caused more muscle fatigue. There’s some thinking that in-game fatigue levels contribute to injury risk since as muscle fatigue increases muscles have decreased ability to divert force from ligaments.

But a lot is also dependent on a person’s particular anatomy and their history from before the velocity increase.


Verducci Effect!

(just kidding)


180 IP seems like an enormous amount for MiLB (these days), no? Are the seasons long enough for that?

karkovice squad

Thanks for expanding on your thoughts about Covey. The xwOBA comparison was a good contribution.

Is it sour grapes to point out I more or less drafted the outline for this analysis in response to GrinnellSteve’s question after Covey beat Sale?

As Cirensica

Why it took you so long?

Nice write up. I also think Covey is up to something. Something good.

Eagle Bones

I’m really heartened by what I’ve seen from him so far. My main concern has been (as you mentioned) the swinging strike rate. He’s probably getting some good sequencing luck right now to have as many Ks as he does. He’s running a 7.8% whiff rate and I believe the rough estimation is that guys typically run a K% about double that (he’s currently sporting a 22% K rate). The good thing is, if you’re running a 60% GB rate and limiting walks, you don’t really need to strike out the world to be useful. I’ve used this comp in the past as a possible good outcome for Spencer Adams, but it may be even more appropriate here: Mike Leake. 7.3% career whiff rate and 51% career GB rate. He’s racked up 16 fWAR in his career with that skill set. Zach Davies is another guy who’s performed pretty well the last two years with a lower whiff rate. I could add more, but the bottom line is he can be useful without adding anything there (and could be REALLY good if he does).

Greg Nix

Jose Quintana has a career 8.8% whiff rate… just saying.

Eagle Bones

Yup, another guy that has succeeded in that range.


Rebuilds are weird man. Gio breaks our hearts, Fulmer imploded, Anderson and moncada (esp moncada) are really struggling… But then a Dylan covey happens. Development is not linear

Reindeer Games

This wedding is horseshit