Milwaukee Brewers’ pitcher Wily Peralta has only been above league average for two of his six years in the majors, and one of those was his rookie season, 2012, when he only pitched 29 2/3 innings. Since then his ERA+ have been 88, 107, 84, and 88, and he has started out the 2017 season with an ERA+ of 90 (ERA 4.88, 1.468 WHIP), averaging just over five innings per start. He had a moderate platoon split in 2016 (left-handed batters had an .880 OPS against him, while righties had an .832 OPS); so far in 2017, the split has been even worse (.715 OPS for right-handed batters, 1.061 for lefties). In other words, he is the model of a back of the rotation starter.
What he throws. Peralta throws a four-seam and a two-seam fastball (“FF” and “FT” respectively), a changeup (“CH”) and a slider (“SL”). Rarely, he also throws a curve (“CU”) that is essentially just a slower version of his slider, without the extra movement most curves have. His fastballs typically hover around 95 mph, with his two-seam fastball, unusually, averaging slightly faster than his four-seam (95.5 mph compared to the four-seam’s 94.9 average), and max out 99.1 and 98.3 mph for the two- and four-seam respectively. The chart below shows his 2016 pitches, but so far in 2017 his pitches have been very similar to last year:
Pitch usage and trends. Peralta’s pitch usage has been very similar so far in 2017 and 2016. About 60% of his pitches are fastballs, mainly his two-seam version, with most of the rest being his slider. His changeup is used almost entirely against left-handed batters, as is his rare curve. When behind in the count, Peralta was more likely to go to his two-seam fastball in 2016, a trend that hasn’t shown up yet in 2017, probably just because of sample size:
Peralta spent most of June and all of July 2016 in the minor leagues, putting up a 6.31 ERA for the AAA Colorado Springs Sky Sox. On his return, his fastballs gained some velocity, with his four-seam averaging 94.2 mph in the first half of the season and 95.6 in the second half, and his two-seam velocity increasing from 95.0 to 96.3 mph. Along with his improved velocity, he had considerably better results, with a 2.92 ERA compared to his 6.68 ERA in the first half.
In 2017, Peralta has picked up about where he left off in 2016 in terms of fastball speed (although changes in pitch tracking between 2016 and 2017 make it hard to compare velocities very precisely), although the results have yet to follow:
Pitch value. None of Peralta’s pitches are very special. In 2016, his four-seam fastball was slightly better than average in terms of total bases per 100 pitches, but worse than average as far as balls per 100 pitches. His two-seam fastball and his changeup were considerably worse than average for TB/100, while his slider was just about average:
In 2017, the patterns are about the same, with the only real difference being his two-seam fastball, which so far this season has been somewhat better than average for TB/100, especially to left-handed batters. On the other hand, lefties have completely teed off on his slider and changeup, accounting for his abysmal platoon splits:
Pitch location. Peralta has very distinct preferred locations for each of his pitches, and those preferences haven’t changed much from 2016 to 2017. His four-seam fastball tends to be up and inside to left-handed batters, outside to righties. His two-seam is the opposite, down and outside to lefties and down and inside to righties. His slider is typically thrown as a strike to LHB, but is down and outside the strike zone to right-handed batters. So far in 2017, his changeup is more likely to be in the strike zone to left-handed batters than it was in 2016: