Everything That ISN'T Wrong With Corbin Burnes, and What Might Be

Through seven starts, Corbin Burnes has a 3.86 ERA. That's underwhelming, from the ace of the staff and a preseason co-favorite for the National League Cy Young Award. Worse, though, is the fact that his ERA doesn't even fully tell the story of his difficult young season. Burnes's strikeout rate has cratered. His walk rate is up. His results are worse almost across the board.

Yet, after looking in all the usual places, it's hard to find the root cause of the trouble. Burnes hasn't significantly changed his release points. He hasn't changed his pitch mix, to either right- or left-handed batters. His velocity is down, but only very slightly, and that's normal for this time of year. His spin rates aren't changed. The movement profiles on his pitches haven't changed in any significant way.

I dug into Burnes's pitch locations. I dug into his sequencing. I looked at videos of his mechanics. None of these things have materially changed in 2023. The spin direction on each of his pitches is essentially the same, and so is the deviation from that spin direction in his observed pitch movement. He's not getting struggling in any particular count, or collection of them.

I think we have to assume that hitters are picking up on something from Burnes. He's tipping something, or hitters are guessing correctly at an outrageous rate. That's the only reasonable explanation for all of this.

The scale of the problem is huge. Right-handed batters are hitting .305/.364/.441 against Burnes this year, and it's not dependent on tremendous BABIP luck. He's only struck out 13 of the 78 righties he's faced so far. That marks roughly a halving of his strikeout rate against them from last year. Hitters are swinging much less often against him this year, and when they do, they're making contact more often, especially within the zone.

With Brandon Woodruff hurt, the Brewers need Burnes to be at his best, in the worst way. They're very fortunate that the rest of the NL Central has stopped and waited for them during this bump in the road, but they need to get back to running the pennant race quickly. The stakes here are high. 

When J.D. Davis came to the plate in the bottom of the first on Friday night, he had a plan. He sat on a low cutter, got it, and drove it out of the park to right field. That requires a talented power hitter to be right about the pitcher's plan of attack, and to bring to bear an approach that works. It looks almost like bad luck. It looks like a good pitch getting beaten. One way or another, though, it's emblematic of the difficulties Burnes has had. Davis either saw something in Burnes's delivery, or was apprised of a pattern that lurks somewhere in his data set. That kind of thing has happened far too often to Burnes so far, and because the cause of the problem is either multifarious or entirely indecipherable, it might not be an easy fix.