Freddy Peralta’s phenomenal fastball

As you may expect, people around baseball were talking Freddy Peralta yesterday. For example, Jeff Sullivan over at FanGraphs posted an excellent article on the Brewers’ newest sensation. I strongly recommend you give that article a look, because it inspired me to analyze Peralta’s delivery further. Sullivan’s piece covers Peralta’s deception, but also touched on something I found particularly interesting: Peralta nearly topped the league in “perceived velocity difference” in his start on Sunday.

Perceived or effective velocity difference refers to a pitcher’s release point, and how it either adds or subtracts velocity from the perspective of the batter. We know that pitchers have different release points based on their different deliveries. Oliver Drake releases pitches way over his head, while Josh Hader throws nearly sidearm. Similarly, some release points are closer to home plate than others.

The closer to home plate you release a pitch, the less time the batter has to react. The less time you have to react, the faster the pitch effectively is. It’s why you hear a 70 mph softball pitch called the equivalent of a 100 mph fastball—you have as much time to react to one as to the other. That same concept explains how Peralta consistently blew 92-93 mph heaters past Major League hitters.

According to Baseball Savant—another wonderful reference—on Sunday, Freddy Peralta’s effective velocity was 2.1 MPH faster than his actual velocity. That shares the league lead in 2018 with 6’8” Pirates pitcher Tyler Glasnow. Rounding out the top five in “Effective Velocity minus Actual Velocity” is 6’6” Steve Cishek, 6’5” Kenley Jansen, and 6’1” Yusmeiro Petit. So Peralta nearly leads the league in a category generally topped by the league’s taller pitchers.

Obviously the 5’11” Peralta’s limbs are shorter than those of Glasnow, Cishek, and Jansen, so how does Peralta’s release point end up so close to home plate? Peralta appears to launch himself towards home plate at the end of his delivery, not unlike the more extreme delivery Carter Capps utilized in 2015.

Anyone who saw Peralta pitch on Sunday knows he wasn’t lunging/hopping quite like that, because no one in the world pitches like Capps did in 2015. That year, Capps posted an effective velocity 2.7 mph higher than his actual velocity. When Capps pitched in 2017, he had reduced the hop now dragged his foot, more like what Peralta did Sunday:

Obviously it’s much more subtle than Capps in 2015, but if you watch Peralta’s lower half, he’s clearly propelling himself toward home plate, pushing off with his back foot and dragging it for a short distance while his right foot is still in the air. That becomes more apparent when compared to more traditional lower-half mechanics like Zack Greinke’s:

Apologies for the less than perfect clip of Peralta. We’ll get better looks at him as his career continues. Another telling shot of Peralta’s delivery is this one from behind:

We can see the bottom of Peralta’s back foot because he’s launching himself toward home plate with that foot. Again, there are similarities to Capps:

And again, a more traditional set up from Greinke, who according to Baseball Savant, effectively loses 1 mph on his pitches due to his release point:

I had fun simulating pitching motions while writing this article. The traditional style, with one foot or the other always planted firmly on the ground, is obviously more comfortable. But imagine you’re a 5’11” teenager (or his coach), and you want to succeed as a starter. You have to get the most out of your delivery. Even without actively pursuing it (like Capps did), it makes sense to settle on a delivery that propels you toward home plate. Not only does the forward momentum help you achieve peak velocity, it also gets you that much closer to the batter.

Peralta averaged 92.7 mph on his fastball on Sunday. That’s not a dominant velocity, but Peralta certainly dominated the Rockies. Peralta’s deceptive delivery no doubt played a large part, but adding a perceived 2.1 miles per hour to his fastball has clear implications.

With perceived velocity and reaction times in mind, Peralta was essentially pouring in 94.8 mph fastballs with a deceptive release. And hey, a mid-90s fastball that explodes from the hand with a deceptive delivery sounds an awful lot like the foundation for Josh Hader’s early career success.

Statistics courtesy of Fangraphs and Baseball Savant