(All stats and pictures are from Fangraphs and Baseball Savant)
Life for Brewers relief pitcher Corbin Burnes hasn’t been as smooth sailing as most would have liked. After putting together a fantastic season last year in the show, it seemed to only make sense that he would improve this year. He was put into the starting rotation to start off the season, which was always the plan for the young pitcher. After struggling through 4 starts, Craig Counsell placed him back into the bullpen, where he had gained a lot of success in the past. Although a couple of appearances have been solid, lately he seemed to have lost it all. The question remaining is, why is this happening?
There are two pitches that Burnes throws the most, the four seam fastball (52.4%) and the slider (31.2%).
First let’s break down the fastball compared to last year. The movement both vertical and horizontal are nearly identical to what they were last year. That is the same when it comes to velocity and the location. However, one thing that has changed for the better, has been the spin rate. It has improved from 2560 (2018) to 2656 (2019), which blew up statcast earlier in the season. From a mechanical aspect, everything is the same or better than it was last year, however the numbers are a much different story.
This year on the fastball it is finding the barrel 10% more of the time, swing and miss is down 2%, K% has dropped 2%, and BB% is up 9%. To put it blatantly, hitters are getting more of a SLG off of it. How can this be, you may be asking, that will come later. Time to discuss the second most used pitch, the slider.
When it comes to the slider this year, everything about it is better, both mechanically and from a number standpoint. The movement he is getting on it this year is crazy insane. First thought on this is, okay throw the slider more, therefore getting hitters off of the fastball. If only if it were that simple.
Corbin Burnes has had no issue this year getting ahead in counts and getting to two strikes. What happens after that, make him look like a completely different pitcher. This was very apparent in his last appearance against the Giants on July 14th. Corbin was consistently ahead in the count, but at the same time allowed 4 hits without recording an out. Two of the hits came off the fastball, while the other two came off of the slider. To break it down a little bit more here is the progression of two at bats that resulted in hits.
|vs Stephen Voght (result- double)||vs Brandon Belt (result- single)|
|Pitch #1 curveball 1-0 count
#2 slider 1-1
#3 slider 1-2
#4 curveball 2-2
#5 four seam fastball 2-2
#6 changeup 2-2
#7 four seam fastball, double (pitch was left low and in, in the strike zone)
|Pitch #1 four seam fastball 0-1 count
#2 slider 0-2
#3 slider, single (pitch was left over the plate, didn’t seem to break)
(Also a double off a slider that was left up on a 0-2 count, and a single off of a fastball on a 2-1 count)
Although Burnes is using the fastball and slider to get ahead in the count, they are also the pitches that falter mostly on 2-strike counts. This starts a whole different conversation when it comes to Burnes. Since he is getting beat on 2-strike counts, the following pictures are the fastball and slider in any count compared to a 2-strike count.
Slider- in any count Slider- in 2-strike count
In these pictures you can see that in any count the slider ends up down in that inside corner most of the time, and further down out of the strike zone. With 2-strike counts it stays up a bit more into that hitting zone, which would make sense why he is getting beat at those times. Burnes gets a lot of swinging strikes when the ball is below the zone, that’s where it needs to be in a 0-2 and 1-2 count.
Four seam fastball- in any count Four seam fastball- in 2-strike count
You can see where this is the same as the slider, with 2-strikes instead of having a bit of a tail and breaking down, it stays up in the hitting zone. Then it turns into a straight 96 mph pitch down the heart of the plate that MLB hitters feast on.
This is where things get hard because there is no statistical reason that explains this. The velocity and spin rate are consistent, and release point seems to have no correlation. The real reason this could be happening could be inside the head of Corbin Burnes. The best guess could be that he is attempting to throw it harder to get the strike out, taking the break or tail out of the pitch. That’s what this issue is beginning to come down to, what’s going on inside his head. Whether he is pressing to get the strikeout, or because he wants to pitch better. A conclusion to the issue is that as much as statistics have flooded the game of baseball, there is still a human on the mound.