Corbin Burnes’ pitch usage continues to evolve

After significant improvement in 2020 thanks to a heavy change in pitch usage, Burnes is surprising us again in very much the same way. But this time it’s different.

I enjoy Corbin Burnes. I don’t enjoy a lot of things about the Milwaukee Brewers, but Corbin Burnes is a fairly significant exception. There’s something to be said about a pitcher with great stuff, who struggles mightily, tweaks his usage, and deploys it in such a way to elevate his performance into the stratosphere. Corbin Burnes is that pitcher.

The fact that this is the second time we’re covering Burnes in less than two months should be a pretty strong indication of the intrigue that he presents. Brian Menéndez covered his sinker usage back in February, examining his essential ditching of the four-seamer in favor of a sinker-slider combo that led him to a 2.11 ERA, 2.04 FIP, and 36.7 percent strikeout rate in the shortened 2020. It was an entire overhaul of everything he’d done in 2019, which featured some pretty miserable output in his age-24 season.

That year was remarkably bad for Burnes. His ERA sat at 8.82, with a 6.09 FIP and a HR/FB ratio up near 40 percent. While his strikeout (29.8) and walk (8.5) rates were solid, he was hit around hard. His hard hit rate was at 42.1 percent, and he ranked in the bottom three percent of the league in Barrel% against. Opposing teams found it easy to elevate against him, with a flyball rate at 31.0 percent. That, in conjunction with the hard contact, is why that HR/FB rate sat at 38.6 percent. Ugly stuff, despite really strong work in generating a 31.9 percent CSW% and high punchout numbers overall. That sinker usage in 2020, though, went a long way toward not only morphing Burnes into a quality starter, but a potentially elite one.

Thus far in 2021, we’ve seen another wrinkle added to the equation: the cutter.

Burnes’ output through two starts borders on absurd. His strikeout rate sits at 48.8 percent and he has yet to walk a hitter. Two starts have seen 20 strikeouts to zero walks. He’s inducing soft contact a touch over 26 percent of the time, and his groundball rate is up near 58 percent, which would represent a wild jump from his previous career norms. Also notable is that this writing is being completed before he faces the offensively inept Chicago Cubs on Wednesday—a team highly susceptible to whiffs and easily the worst offensive club in the earlygoing by way of team wRC+ (63).

The transition from 2019 to 2020 was an overwhelmingly positive one. Obviously. And what makes his early start in 2021 so interesting is not the fact that he’s managing to replicate his output, but potentially exceeding it with yet another significant usage change:

Burnes’ 2020 was obviously marked by the spikes in both sinker and cutter usage. And thus far in 2021, it’s the cutter that has continued to show the largest increase, to the point where he’s throwing it almost half the time (49.1 percent). The sinker is at just 14.5 percent after last year’s jump. For comparison, the two pitches were at a 33.1/31.5 split, respectively, in 2020. The four-seam fastball is absent from the equation almost entirely after its sharp decline in 2020 (1.2 percent). It’s been registered as having been thrown only twice.

So essentially Burnes has gone from fastball-slider reliant to utilizing the sinker-cutter combo to set up the slider to deploying the cutter to set up everything else. The sinker and slider are still very much present. As are the occasional change and curve. It’s a five pitch mix, having thrown out the four-seam, but the rate at which he’s thrown that cutter has been *wild*.

You can’t argue against the results, though.

One really important aspect of all of this is what it’s done for his secondary pitches. In leaning so heavily on his cutter, Burnes has seen continued increases in Whiff% against his slider, curve, and changeup (each of which he’s throwing anywhere from 10 to 12 percent of the time):

Burnes has always had strong numbers in the strikeout game. But relying so heavily on the cutter and—to a lesser extent at this point—the slider has allowed for sharp increases in not only whiffs, but overall strikeouts for the other secondary stuff. And if he isn’t generating a whiff on one of those pitches, he’s sure as hell making sure that contact is on the ground:

The cutter itself is doing a good enough job of ensuring that any contact makes its way onto the infield grass, but those numbers with the other stuff are allowing Burnes to experience immense success in the early-going of 2021.

Opposing hitters are still getting the ball in the air over 30 percent of the time. But line drive contact is at just about five percent. And we already talked about the groundball rate. The latter two are the most notable changes, and which likely bode the best for Burnes moving forward. It’s not as if any of his pitches have changed significantly or there are any alarming trends elsewhere. The movement on his pitches has remained relatively constant, as have many of his contact trends, with the exception of the LD% and GB%. It’s all about the usage. Burnes has determined his best method of deployment and has used it to the absolute pinnacle of potential success so far in 2021.

Obviously we’re looking at a small sample, as is the case with anything this early in the year. So maybe a GB% up near 60 or cutter usage at almost 50 percent aren’t sustainable. But what makes Corbin Burnes such an interesting pitcher is how that usage changed so much in 2020, yet continues to change just as much early in 2021. What it’s done is lead to the evolution of a “stuff” guy from one who was able to post good strikeout rates, with fairly damning peripherals, to a legitimate frontline starter, whose reliance on the cutter not only generates consistent strikes, but massive groundball contact and the subsequent success of his secondary pitches.

(Small Update: Burnes’ start against the Cubs yielded six innings and 10 strikeouts. There was not a walk to be found here, either. The cutter usage? 52 percent.)

Randy Holt is a contributing writer for Beyond the Box Score. You can follow him on Twitter @RandallPnkFloyd.