Whenever one of the bigger prospect gets called up to the Pittsburgh Pirates, we do an article describing who they are and how they made their way to the majors. We have never had a second chapter to a “Book On” article because there was never a need before. Mitch Keller got his Book On article back on May 27th, but this current version of Keller coming up today is not the same Mitch Keller we saw back then.
Keller made three starts in the majors, getting hit around in the first two games, followed by a decent third outing, albeit against the worst team in baseball, the Detroit Tigers. Anyone who saw the games, saw the biggest issue. Keller was throwing a lot of fastballs and they were getting hit hard. That has always been his attack plan in the minors and it obviously worked well. He would throw his fastball often the first time through the lineup, usually only going to the curve with two strikes. Then once he was going through the lineup a second time, he would mix his pitches better, but he would still be using the fastball more than he used all of his off-speed pitches combined until the later innings. The problem he had in the majors is that the damage was already done before he got back to the top of the lineup, so those who were watching, mainly saw fastballs.
Keller was sent back to the minors in late June and he has made eight starts since then. His first three starts back were minimal improvements in pitch usage, but fairly similar to what we saw previously. However, his last five starts have shown a noticeable difference. If he doesn’t stray from what we saw those outings, then you won’t be seeing the same pitcher as the one in the majors.
Here are the pitch usage numbers from those last five games, noting that the slider and changeups have similar speeds, so bad camera work in two of those games made it tough/impossible to see which pitch was being thrown on about 5-6 occasions. He rarely throws a changeup to a right-handed batter, so that helped the educated guesswork a little. I also started tracking specifics a little late in the first start, but the numbers are fairly close. Once I noticed that he was using all of his pitches through the first two innings, I started tracking pitch-by-pitch. It’s a big enough sample size though that being off by 2-3 on any pitch doesn’t make a difference to the overall picture.
Here are the games individually:
Total Pitches, with percentages:
FB: 223 (47.5%)
CV: 121 (25.8%)
SL: 111 (23.7%)
CH: 14 (3.0%)
For reference, coming from someone who has watched 50+ starts from him in the minors, I noticed he was throwing more off-speed pitches in his June 24th start, which was his first game back in the minors. The breakdown from that game was:
FB: 52 (55.3%)
While he was using his curve at a high rate, it was still an outing that he used his fastball more than any of his last five games, but also less than he would normally use it in the past.
So the “Book On” Keller has changed since he last pitched in the majors. He goes to his breaking balls more often than ever in his career. He mixes his pitches right from the start of games, and his changeup has gone from about 10% usage to almost non-existent in some starts. That’s a big difference from the pitcher who would go to his fastball around 85% of the time early in the game, while never really mixing his pitches well until the later innings.
Will he continue this recent trend? That’s something that we will find out tonight.