Where Has Taillon’s Curveball Gone?

I began last week ?s post by examining how the Pirates rotation has moved away from their bread and butter fastballs for sliders in the early parts of the season. Chris Archer ?s slider-heavy approach is a big reason why, and Joe Musgrove is shifting the pendulum by opting to throw the slider more often than his cutter. Then there is Jameson Taillon.

We can joke that Taillon is the number five starter when compared to the torrid starts of his rotation brethren, but he ?s still doing well. His 3.12 ERA and 3.36 FIP are right in line with his 2018 totals, and he really only has had two bad innings. The first was being kept in a little too long in Cincinnati on opening day. The other was when the defense completely crapped out on him in Chicago.

He ?s certainly in a better place than he was one year ago. It was around this time in 2018 when he began to slump, leading to him adding a slider to his repertoire. Taillon spoke about that experience with FanGraphs ? David Laurila recently, saying:

?I had two bad starts last year, and at that point I felt like I was a two-pitch pitcher. I was fastball-curveball. I was pretty much asking my curveball to be a strike pitch, a swing-and-miss pitch, an out pitch, a weak-contact pitch. It had to take on a lot of different traits. I figured slider-cutter ? some version of that ? would be the play. So I started throwing it in catch, and then in a bullpen or two. After about a week, I broke it out in a game. ?

That slider turned Taillon ?s season around. Batters were not offering at his curveball because they knew he would have to come in with a heater eventually. Once he added the slider, his pitch selection radically changed.

The slider became Taillon ?s new number two. He did throw his curveball a little less after he started the new pitch, but he really de-emphasized his fastball and changeup. He was still essentially a three pitch pitcher, but two of those pitches were now breaking balls.

In the early parts of this season, he is using the slider even more. If you divide his four-seamers and two-seamers into two separate entities, then his slider is the most used pitch so far. The difference this time his curveball is starting to go M.I.A.

Compare his curveball and slider usage per game since May 27.

Taillon was very excited with his new pitch in his first couple starts, so he was very slider-heavy. Starting around June 7, it averaged out that he used his curveball roughly 20% of the time and his slider 25%. There are obviously some peaks and valleys, but he hovered around there for most starts. This year, it ?s about one-third sliders and 15% curves. The divide between the two pitches has never been this drastic for this long a stretch of starts. It ?s a very different dynamic.

He also has a very different approach with two strikes. From May 27 on, he threw his curveball just as often as his slider when he had two strikes.

And the curve was the better pitch for getting strike three.

This year, he ?s struck out just one batter on the curve. The slider isn ?t just a pitch he throws when behind in the count or to get a ground ball, like he told Laurila. It ?s become his kill pitch of choice. This is his two strike pitch breakdown this year:

The curveball usage has dropped in half with two strikes, even though it was one of his best pitches in that scenario last year. Meanwhile, Taillon ?s strikeout rate has dropped from 22.8% to 18.4%, and his two strike whiff/called strike rate when he has two strikes has gone from 20.7% to 17.2%. He ?s still getting to two strike counts, but he is not finishing batters off as often with his slider heavy approach.

Now this is not to say that Taillon ?s slider is a bad pitch or he ?s struggling this year. Far from it. His .258 xwOBA on the slider is a little better than average, and batters are only hitting .200 against it. He may have the highest ERA on the staff at the moment, but it ?s a long season. He will not be the outlier.

But for those looking for him to take the next step, he has not done that so far in 2019. It has only been five starts, but it looks like he is getting into some new habits. It ?s too early to say if they are bad habits, but he got into trouble last year by relying on the same looks too often. This could be a case of same problem, new year, but with a different pitch.