Which pitcher in baseball this year has been the best at making hitters swing and miss at his fastball? The obvious answer is the correct answer, at least by one measure -- Aroldis Chapman has induced the highest rate of fastball swings-and-misses. That's one of those things that can happen when you can throw 102 miles per hour. By another measure, though, the answer would be Ernesto Frieri. By whiffs over pitches, the leader is Chapman. By whiffs over swings, the leader is Frieri. Both margins are small. Things could change, as it's July.
It's not essential, but it's important for a pitcher to be able to make hitters miss his fastball. A fastball that's difficult to hit gives a pitcher a good strikeout foundation, and it allows him to become lethal with quality secondary stuff. One of the things that made and makes Michael Pineda so promising is that his fastball runs a low contact rate as a starting pitcher. He's been effective even without a quality changeup or consistent slider; improve those, and Pineda could be untouchable. A pitcher with a challenging fastball is a pitcher with a very high ceiling.
So it's always interesting to look at the pitchers who induce the most fastball whiffs. Fastballs generally get fewer swings and misses than other pitches, as fastballs generally move less than other pitches, but fastballs tend to be a guy's bread and butter. He who has a good fastball is in an advantageous position.
As noted, so far this season, Ernesto Frieri has posted the lowest fastball contact rate. He zips the ball up there, he works up in the zone, and he has a short-arm delivery. Chapman's right behind him, and Chapman has probably the most famous fastball in the game. Chapman just classically overpowers the hitters that he faces. Also near the top of the list is Craig Kimbrel, who reaches the very high-90s. None of these names are surprises, provided you've heard Ernesto Frieri's name before and have a vague idea of what he does.
But someone weird slots in at number three between Chapman and Kimbrel. The average reliever has allowed an 81-percent contact rate on fastballs. Joel Peralta has allowed a 69-percent contact rate on fastballs. Joel Peralta, who you might know only for getting ejected and suspended.
Here's what Joel Peralta's fastball looks like in a .gif:
Here's what Joel Peralta's fastball looks like in a slow-motion .gif for some reason:
Looks like it's got some zip, right? Well, sure, even the slowest major-league fastball goes faster than someone speeding on the freeway. Would you be able to tell the difference between 90 miles per hour and 100 miles per hour in a .gif? I guess that's a question for another day. What matters here is that Joel Peralta's fastball averages about 90 miles per hour. You wouldn't expect an "ordinary" fastball like that to generate the swings and misses that Peralta's fastball does.
This is what I was referring to with the skinning of cats, which I guess used to be a common and accepted practice when people were inventing idioms. Hear that a guy's fastball is hard to hit and your immediate assumption will be that he throws a blazing heater. You'll imagine something like Chapman's fastball, or Kimbrel's fastball. Something overpowering, the way everybody wants their own fastball to be. Peralta doesn't have that fastball, but he gets the results. What do we take away from this?
Peralta has a few tricks. As you can see in the .gifs above, he has deception working in his favor. He manages to hide the baseball behind his head moments before release. He throws his fastball almost exclusively outside to righties and outside to lefties, with particularly strong command. And very interestingly and unusually, Peralta doesn't throw his fastball all that often. Roughly 43 percent of Peralta's pitches have been fastballs. The rest have been curveballs or splitters.
Two-thirds of Kimbrel's pitches are heaters. Nearly 90 percent of Chapman's pitches are heaters. Frieri throws his heater like Chapman throws his heater. Peralta has thrown a fastball as often as Adam Wainwright hasn't.
So, okay, wait, hold on. If Peralta's fastball is so effective, why not throw it more often? Isn't Peralta only holding himself back? It stands to reason that Peralta's fastball is so effective in part because he limits its usage. He doesn't have a primary pitch. He has three pitches he'll throw in any count. Later in his career he learned to pitch backwards, and now just 49 percent of his first pitches have been fastballs. When behind 1-and-0, 37 percent of his pitches have been fastballs. When ahead 1-and-2, 45 percent of his pitches have been fastballs. By and large there's no figuring out Peralta's sequencing, leaving hitters to try and differentiate between three very different pitches thrown from similar release points. With the ball having been hidden behind Peralta's head.
Aroldis Chapman probably has the best fastball in the world. Now that he's figured out where it's going, he's almost literally unhittable. It's absurdly impressive that Chapman generates his numbers when hitters mostly know what he's going to throw. On a pitch-by-pitch basis, though, it's insane that Joel Peralta's fastball can even compare. Peralta isn't nearly as physically gifted, and his fastball has the same average velocity as J.A. Happ's. It's about the quality of the pitch, and in how you wield it. Joel Peralta wields his fastball with great caution and care, and in that way it ranks up with some of the most overpowering fastballs in the league.
It's no great shock that velocity isn't the only thing that matters when it comes to making hitters miss. Pitchers who can miss bats with hard fastballs are of a certain level of interest. Pitchers who can miss bats with more ordinary fastballs are of a higher level of interest. Joel Peralta gets it done like few others.