Over his last five starts, right-hander Wily Peralta has lowered his ERA from 6.08 to 4.61. He’s only allowed four earned runs over that stretch (33.1 innings), and on Monday, I pointed out how Peralta drastically turned his season around last summer, which was roughly the same time as this year.
We’ve noted how his command has slightly improved and how his strikeout rate has increased over the last five starts, but it’s not enough to merely state Wily Peralta has increased his strikeout rate. It’s much more important to understand why his strikeout numbers have experienced a slight jump.
The 24-year-old hurler features a mid-90s sinker that can be devastating to opposing hitters. Few guys regularly run a true sinker into the 94-96 mph range, but at the big-league level, it’s rarely enough to have one plus-pitch. His success hinges upon the effectiveness of his slider. His breaking ball was largely absent earlier this season, and when he did throw his slider, it was more of a show-me pitch rather than a pure secondary offering. He’s gotten more comfortable with the pitch, though, and he’s featured it more heavily as the season has progressed.
The above chart depicts how Peralta would often throw his slider fewer than 20 times per game — despite the fact he was still throwing 80-100 pitches — but that number has increased to 20-30 (or even more) in his last ten starts. Though it’s partially speculation, it’s likely not a coincidence his increased reliance on his slider has coincided with a 3.06 ERA in his last ten starts.
Featuring more sliders is great. The real test, though, comes with the effectiveness, and Peralta has been throwing his slider much better in recent weeks. He’s inducing more swinging-strikes with his slider. That has proven to be a struggle for the right-hander throughout the season, but he has missed more bats in recent starts and greater success has understandably followed.
Perhaps it’s not groundbreaking to learn Peralta has gotten more swings-and-misses with his slider since he’s started to throw it more often, but it’s been a significant factor in his recent improvement. His slider was one of the main reasons he punched out eight Diamondbacks during his most-recent start on July 14. He was able to bury his breaking ball against left-handed batters, which is something he struggled to accomplish earlier in the year.
The interesting thing about Peralta’s slider is that he actually possesses two separate versions of his slider. One is a slower, gentler pitch that’s meant to find the strike zone earlier in the count, while the other is more violent and more vertical and serves as his put-away pitch when he’s ahead of the hitter.
Here’s an example of the first version of slider mentioned above. It came against Brandon Phillips of the Cincinnati Reds in his complete-game shutout on July 9.
In this instance, he was able to generate a swinging strike, but this pitch was meant to avoid the fastball and get ahead in the count. Peralta generally throws this version of his slider in the 83-85 mph range. Occasionally, this pitch can get a little flat on the right-hander, and it can be more hittable. On this pitch to Phillips, though, Peralta was able to get on top of the pitch and achieve the two-plane movement that’s desired on a slider.
It’s slight, but it doesn’t have to be anything dramatic for Peralta to be successful with it. The pitch is meant to be a get-me-over slider earlier in the count, so opposing hitters cannot simply sit on his sinker — which is obviously what Brandon Phillips was doing in the above clip. Peralta fooled him with the slider, and it allowed him to position himself in the driver’s seat for the at-bat.
His other slider is not meant to be thrown in the strike zone. It’s his two-strike wipeout slider for when he’s trying to strikeout the opposing batter. A good example of this slider came against Jason Kubel of the Diamondbacks on July 14.
Peralta has no trouble getting two-plane movement on this slider, as it doesn’t break as much horizontally as it does vertically. It’s very difficult to command, but it can be a true difference-maker for him when he’s throwing it properly. It breaks sharply and is thrown with more velocity — which can be seen in the above graphic, as his put-away pitch to Kubel clocked at 87 mph.
At times, it’s been frustrating to watch Wily Peralta this season. He has a chance to be a valuable mid-rotation starter for the Brewers over the next half-decade — his pure stuff makes that obvious — but a combination of bad luck and inconsistent performance led to an ERA north of 6.00 for much of the early season. He’s slowly bringing that ERA back down to a respectable level, though, and rekindling some of the hope that existed prior to the 2013 campaign.
If his slider becomes a more consistent, reliable part of his repertoire on the mound, he could be a solid number-three starter with some upside next year. And with Yovani Gallardo and/or Kyle Lohse potentially available on the trade market this summer, the Brewers need someone to step up and become a consistent, effective starter. Peralta has taken steps in recent outings to be that guy. It will be enjoyable to watch how he continues to develop throughout the remainder of the season.