Making an Ace: Evaluating Wily Peralta’s Struggles | Disciples of Uecker

Disciples of Uecker

We'd like to go to the Playoffs, that would be cool.

Disharmonious to prior seasons, this year’s Brewers team is painted with a common tone that seems to have already latched itself as the tagline of the 2016 campaign: uncertainty. The most recent case came last week, when Craig Counsell named Wily Peralta as the Opening Day starter. Being submerged in rebuild mode and with the vacancy of an ace being existent on the pitching staff, Counsell could have taken a number of different approaches in selecting a starter, eventually rolling the dice with Peralta. Following a 17-win season in 2014 that implemented glimmers of hope that development into an ace could be around the corner, he experienced a setback in 2015 that was jolted by an oblique injury that consumed parts of his season. Peralta has now been provided a new accolade in his career by being named the Opening Day starter, although an array of obstacles need to be hurdled before he can fully assert himself into the discussion of a dominant ace.

Analyzing his path to the Majors, Peralta’s fastball has been the oil that makes the machine go. He has used his roaring speed to blow pitches past hitters, leaving them standing in their shoes with a hole in their bat. Looking at how he has enforced his fastballs, his four-seam and two-seam have been his two most frequent pitches in his career, but through the years it has oscillated between good and bad. Let’s compare his usage of his four-seam in 2014 compared to 2015:

Season Pitch Pitches H SO AVG minVel maxVel Vel
2014 FA 1101 58 35 .243 88.0 99.2 95.6
2015 FA 562 48 9 .400 88.7 97.4 94.1

The obvious eye sore that stands out from this data is opponents’ batting average, which registers as an outrageous difference between the two years. In 2014, batters hit only .243 against Peralta’s four-seam, while a year later, contact became much more prevalent as their average soared to an astounding .400. During his career, much of Peralta’s hype has been by way of the blazing speed of his fastball. Though he still finished with an average velocity of 94.1 MPH on his four-seam last season, it was an entire 1.5 MPH difference compared to his 2014 velocity, which steadied itself at 95.6 MPH. Just that slight of a difference can transcribe into an apex of problems, which unfortunately occurred for Peralta.

Here’s a graph that represents the dip in Peralta’s velocity with his fastball:

velocity_map_wilyA 1.5 MPH difference in velocity resembles an unfavorable change for a pitcher, especially one like Peralta that relies heavily on speed to baffle opposing hitters. In fact, Peralta’s K % when using his four-seam nearly sliced in half from to 2014 and 2015. In 2014, it cataloged at 12.8 percent and then plummeted to a career-low 6.6 percent the following year. His BB/K ratio also increased from 0.80 to 1.11 as well.

Lefties have continued to provide a number of problems for Peralta throughout his career and 2015 was no different. Compared to righties, left-handed batters hit 16 points higher than righties (.305 compared to .289). Another glaring concern regarding Peralta and his foes from the left side is the OBP duel. From 2012 forward, OBP from the left side of the plate has continued to climb. In fact, lefties have experienced yearly extrapolating success in nearly all of the four offensive categories below:

Season vs L AVG OBP SLG wOBA
2012 vs L .265 .333 .306 .290
2013 vs L .255 .342 .411 .333
2014 vs L .300 .349 .471 .361
2015 vs L .305 .355 .534 .376

Compare this with the same years but against right-handed hitters:

Season vs R AVG OBP SLG wOBA
2012 vs R .208 .304 .260 .261
2013 vs R .263 .333 .358 .310
2014 vs R .213 .293 .313 .277
2015 vs R .289 .366 .430 .349

Correlating the two tables, a pair of facts can be interpreted. First off, no rising theme of stats exist with right-handers as they do with left-handers. Peralta has been able to keep his numbers in check and maintain them at a reasonable pace, which cannot be said for with lefties. The other understanding that needs to be grasped represents itself in the sheer numbers – the statistics are two completely different stories. Lefties are a horror story for Peralta. New pitching coach Derek Johnson has his work cut out in front of him in developing Wily along the path of restoring his damaged history.

As one can expect, accuracy plays a massive role in determining Peralta’s fate between lefties and righties. Here’s a comparison of his heatmaps and strike percentages versus lefties and righties from last year:

wily_heatmap_lefties wily_heatmap_righties

As shown here, accuracy resembles a glaring discussion as to why Peralta has struggled with lefties. In the strike percentage heatmap charts above, take a look at his capability to paint the inside on righties compared to an inability to do so with lefties, resulting in frequent contact, which then unrolls into further troubles. Pitch location will be a necessity for Peralta to focus on this season, particularly the task of working inside on left-handed hitters.

Moving on to batted balls, Peralta experienced a slight dip in ground ball percentage, as shown on the spray charts below, dropping two points from 53.6 percent to 51.6 percent:

battedballs1415

 

Now, cycling back to the concern regarding his conflicts with lefties, here are the spray charts scrutinizing the differences between both sides of the plate from last season:

battedballsleftiesrightiesSafe to say there’s more red emerging from the bats of left-handers.

One of the other possibilities Peralta may approach to manage the amount of success that hitters have against him is by garnering a higher usage rate with his changeup. Since he has relied massively on the velocity of his fastball to aid him with achievements in the Majors, Peralta has not really refined on flourishing a steady groove with off-speed pitches. Last season, his changeup chronicled as his fourth-used pitch in his arsenal. Throughout his career, he has only used his changeup six percent of the time. Developing more utilization and familiarity with off-speed pitches may transition into higher tendencies in lowering offensive rates from both sides of the plate. Here is his pitch usage rates from last season:

Season Pitch Pitches AVG
2015 FT 588 .299
2015 FA 562 .400
2015 SL 496 .218
2015 CH 101 .208

Hitters struggled last season with Peralta’s changeup batting only .208 against it, providing another reason as to why he should work on conducting it more frequently. If he wants to gain the notion of being viewed as an ace, he will need to be able to turn the tables by cultivating off-speed with accuracy on a consistent basis.

The Brewers are at the forefront of hoping that Peralta reverts back to his old ways and experiences a bounce-back 2016. Despite a disappointing 2015 campaign, Peralta still showed flashes of promise, especially in his pre-injury work (3.90 ERA, 1.40 WHIP, 15 percent strikeout rate). Milwaukee’s rotation lacks a go-to pitcher, something that becomes mandatory for all teams vying for a playoff spot. Though the Brewers are on the outside looking in concerning playoffs and will be for a few more years, by giving Peralta the reigns of being the Opening Day starter, Counsell may have sparked a mentality edge for him moving forward as he embarks on polishing his game.

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