That Wily Wily Peralta

The outlook on Wily Peralta hasn’t drastically changed over the last year. Coming into 2014, he was a young arm in possession of some tantalizing skills: elite velocity, two plus pitches, and a tremendous groundball rate. He repeated all of that in 2014 en route to his best season yet, but there are still some issues to iron out. His season essentially breaks up into three parts, with his success against left-handers setting the tone in each.

He got off to a great start with a 2.12 ERA in his first 10 starts. The wheels came off for an eight-start run in early-summer, and he was tattooed for a 6.38 ERA before closing out the season with a 3.00 ERA in his last 14 starts, as he held the opposition to 29 earned runs – 13 of which came in two ugly starts at the end of August. His OPS against lefties in the three parts were .681, 1.063, and .759. The blowup in the middle was fueled by the slider getting uncharacteristically smashed for a couple of weeks, as all five homers that lefties hit off the pitch came during that stretch. He allowed a 1.420 OPS with the pitch, despite a 10-to-1 strikeout-to-walk ratio in the 24 plate appearances. Small samples can really hurt!

It wasn’t just the slider that failed him during those eight starts. He couldn’t get lefties out with anything, as the fastball allowed a .937 OPS, and the changeup was at 1.308 OPS. Perhaps it was the schedule that did him in. He faced some of the toughest left-on-right teams in the league during that run, including the Rockies twice (1st in lefty OPS v. RHP), the Blue Jays (8th), the Mets (11th), and the Twins (13th).

The Cubs (19th) and Phillies (25th) were in there too, and while neither was an overall juggernaut in left-on-right OPS, it was almost exclusively southpaw damage in both outings, with Anthony Rizzo going deep twice for the Cubs, and Chase Utley, Ben Revere, Dom Brown, and Cody Asche all collecting two hits apiece for the Phils. Of course, if you want to be an upper-level pitcher, you have to find a way to handle guys like Revere, Brown, and Asche. You can get a pass for Rizzo and Utley, but mediocre or worse lefties need to be shut down.

It seems like his path to consistent success against left-handers is less about the changeup (though if it developed, that would definitely be a big help), and more about the fastball. In none of his three seasons has the fastball held lefties to an OPS under .800, while league average is .780. The league mark drops to .695 when you’re looking at fastballs of 95+ MPH, so Peralta is even further behind the curve with a heater that averages 96 MPH. There isn’t one single way to generate this success, as the top guys have varied approaches.

Yordano Ventura had the most plate appearances ending with a 95+ MPH heater against lefties at 263, 20 more than Peralta. He doesn’t have a clearly carved out approach, particularly with his horizontal usage, but he does tend to pump the high fastball. Garrett Richards netted a .605 OPS on 95+ MPH pitches against lefties in 218 PA with a very clear approach: down and away. More than 50 percent of his 819 such pitches were in that area of the zone. And while he did hit other regions of the zone vertically, the “away” aspect of his down and away approach was a major focus with 62 percent thrown outside.

Chris Archer favored the up and away approach with his fastball against lefties. They hit to a .596 OPS all told on his 95+ fastball, including a .533 on those that were up in the zone, a .391 on those away, and a .415 on the quadrant that combined the pair (upper right of the zone from the pitcher’s viewpoint). I think this approach is the one that would suit Peralta best. He already works the slider down in the zone most of the time, so the change in eye level adds to the effectiveness of both pitches. Peralta wouldn’t necessarily have to focus the slider down and in, either. Archer’s is devastating when it is down and in on lefties, but he works it down and away a lot, too and it is still fantastic (.516 OPS with a 67% GB rate).

Peralta is still in the development phase of his career (hell, so is Archer which makes him really scary for the opposition) so don’t necessarily look at what he can’t do and assume that it’s set in stone. There is still time for the changeup to develop, too. When he does work it down and away, it is really good, but he doesn’t have the command of it down just yet, and when it leaks over the heart of the plate, it gets crushed. This is a growth stock that still holds real risk, but the potential has enough allure to invest in all formats, especially at a price where the risk is mitigated (18th-19th round in NFBC).

We hoped you liked reading That Wily Wily Peralta by Paul Sporer!

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Paul is the Editor of Rotographs and contributes to ESPN's Daily Notes. Follow Paul on Twitter @sporer and on Twitch at sporer.

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Thanks for this analysis. Digging into pitch use, effectiveness, splits and chunks of seasons is fascinating. We’ll have to see if he makes adjustments.