Breaking down Corey Kluber’s spring starts

One of the challenges of spring training is figuring out what to focus on and what not to. There’s a great story about how Joey Votto spent an entire week of spring hitting every ball he could down the third base line, because he was experimenting with how long he could wait on a pitch before swinging. We don’t know what guys are working on, how seriously they’re taking the spring, and the competition level is variable.

All that said, there are instances where we can undergo serious analysis, and one of those instances is starting pitchers coming off of injury. Thankfully, the Yankees have more than a couple of those guys, and when it comes to Corey Kluber specifically, we can pull apart his early spring and see if he’s a different pitcher than the Cy Young winner he used to be.

It’s tough to take any one of the last couple seasons Kluber’s thrown, since injury has cut him down so much. What we can do is combine some seasons and look at trends, like his pitch usage since 2018:

Kluber’s always been a guy that strayed from the four-seam, and used three pretty similar pitches. It’s often hard to distinguish between his cutter, slider and sinker, with those former two often interchangeable by pitch tracking. That usage has been pretty much exactly the same so far in spring:

The one early change is a notable uptick in four-seam usage, albeit over less than 100 pitches. I think there are two possible explanations for this. One, as Kluber re-establishes himself, the four-seam is a test to make sure his arm can physically stand the stresses of pitching. He’s older, has battled shoulder problems, so might as well just throw the most basic pitch early to see if his body can still hold up.

The other option, as I see it, is this is a conscious choice, in line with what a lot of other Yankee pitchers do. The staff as a whole takes advantage of fastballs up in the zone, and at least yesterday, Kluber was working above the letters, even if he wasn’t necessarily in the zone:

I tend to think it’s the former. Kluber hasn’t really picked up any spin over his 2018 numbers, and while 2300-odd rpm isn’t a terrible spin rate for a four-seamer, it’s far from the sky-high figures someone like Gerrit Cole or Jameson Taillon can generate with their heaters. Without a change in that department, I find it hard to imagine Kluber will stray too far from the cutter-sinker-slider trio that’s been the backbone of his approach for years.

Kluber’s done just fine in spring, and seeing him throw 54 pitches yesterday was a welcome sign that there are no lingering injury affects from his lost 2020 season. He’s still a 34-year-old pitcher, and there are good reasons to be skeptical that he can recapture some of the Kluber Magic we used to see. Through two starts, though, he’s falling back on the same good habits that made him such a good pitcher in the first place, so there’s room to be optimistic as well.