Saturday, August 1, 2020

Gerrit Cole's First Couple of Starts for the Yankees

Now a little more than one week through the (mess that is the) 2020 MLB season, we have seen Gerrit Cole take the mound for the Yankees on two occasions. Cole was the biggest free agent on the market and as such he signed a 324 million dollar contract with New York, the largest ever for a major league pitcher. Cole is coming off of two seasons in Houston where, after making some meaningful changes to his pitch mix, he blossomed into an ace-level starting pitcher to the tune of a 37.3 percent strike-out rate, a 6.9 percent walk rate and accumulated 13.4 wins above replacement over 412 and two thirds regular season innings, per FanGraphs. 

Having seen both of his starts thus far, I thought it would be a fun exercise to dig through some of the pitch-level data, even with the season's future hanging in the balance and see if I can spot any differences in his pitch characteristics thus far between his tenure in Houston and his starts with the Yankees. Before I take a look, I should provide the caveat that looking at just two starts worth of pitches should be taken with a massive grain of salt, on account of the extremely small sample. 

First, here are his average velocities by pitch type and the standard deviation of those velocities: 
Not much of a change at all. Even the standard deviations are very close. Next, pitch usage both in total and by count: 
Cole has been much more reliant on his four seamer in the early going, especially in hitter's counts. This might be some indication that he does not trust his secondary pitches yet for high leverage pitches, which given the unusual circumstances around the start of the season is not especially surprising. Still, given his success the last couple of years, I would hope as the season (hopefully) progresses, he begins to lean on his slider and curve more often to keep hitters uncomfortable even when they have the advantage. 

To the eye, Cole has not been very sharp (relative to our enormous expectations) and sure enough he seems to have some issues commanding the fastball and curve.
He really seems to be making an effort to bury his curve, but given his whiff rates in the past on the pitch he would probably see some benefit to putting it more in the strike zone and forcing opposing hitters to swing. The fastball has been left over the plate way too often thus far, and his whiff rate has suffered as a result (37.6 percent last year, 22.0 percent through his first two starts. In 2018 it was 29.7 percent, so some regression from last year's figure is to be expected). The slider seems fine, but his curve ball is generally his breaking ball of choice against lefties. In order to turn over the lineup more than a couple of times effectively, he needs to be more effective with that curve. Maybe you can attribute some of this apparent lack of command to where he is releasing the ball?
Looks like he is releasing the ball closer to his head on average. There is still overlap between the release positions in Houston and New York, but there is a clear separation between the clusters. Here is the same information in tabular form: 
There is a difference, but it is too early to attribute this difference to a mechanical change versus just natural variance in his release points. In the release point plots above, there is more variation in his release points from his Houston days, but also more pitches facilitates a larger probability that various release points deviate from the mean. If you consider his release point data from Houston as a distribution of possible release points for Cole, it is feasible that the data from his pitches in New York would fit in that distribution, disproving the idea that this is a conscious mechanical change and instead is just a product of variance. Nevertheless, I would be interested in hearing whether or not he made this tweak on purpose or its just the product of a small sample of pitches. Finally I looked at Cole's pitch movement profile and found that nothing had really changed in his first two starts. 
And the data in tabular form: 
Given the movement has not changed nor has the velocity, as I explained above, the apparent lack of command through two starts is probably the main culprit of his strike-out rate falling 10 percentage points since compared to his time in Houston and going from 0.93 ground balls per fly ball to 0.35, per FanGraphs. His swinging strike rate is down (about 27 percent) as is the rate at which he puts away hitters with two strikes.
All of this is not cause for alarm. Cole has been very good through two starts, just not as dominant as we have been used to. But we are also talking about only two starts and two starts after a four month layoff. Given what has transpired in the world of baseball the last few days, I would be much more worried about seeing Cole pitch at all for the rest of 2020. 

No comments:

Post a Comment