Aroldis Chapman's new toy is actually unhittable

Aroldis Chapman has always been a quality reliever. His signature pitch has been his four-seam fastball, which has averaged 99.6 miles per hour during his time in the majors. Up until 2018, he was primarily a two-pitch pitcher, throwing fastballs and sliders with the rare changeup thrown in. In 2018, he incorporated a sinker that he throws around 10 percent of the time. That sinker also averages over 100 miles per hour. And in the last two years, he’s added another pitch to his repertoire that has been a game-changer: the splitter.

Usage and velocity

Chapman has stepped up his usage of his splitter in 2021 after experimenting with it last season.

Season

Usage (%) MPH

2020

1.5

91.1

2021 11.7

89.9

With his fastball and sinker averaging around 100 miles per hour, he has a 10 miles per hour difference when he uses his splitter. Add that to his slider which averages around 85 miles per hour and it makes it near impossible to hit him on a regular basis.  He only threw three splitters in 2020 but swings-and-misses on all three. So far this season he’s thrown 13 of them, and of the seven that have been swung at hitters have missed six times (85.7 percent whiff rate). All six of those misses resulted in strikeouts. Over the past two seasons, his splitter has not been put into play (10 swings, 16 total pitches). Overall, this means that 16 of those splitters generated swings, and only once has a batter made any contact. https://twitter.com/PitchingNinja/status/1385415071703183365?s=20

Movement and location

In addition to the velocity differential, the keys to Chapman’s success with the splitter have been a combination of movement and location. A splitter is typically thrown down in the zone, and Chapman has been pounding this location. As you can see, his fastball is typically higher up in the zone while his splitter is down. Imagine getting a 100 MPH heater up in the zone followed by a nasty splitter at your knees. 

Of all pitchers this season, Chapman’s splitter has been the best in terms of run value per 100 at -6.7 (less is better for pitchers). Shohei Ohtani is second at -5.5.  In terms of movement, Chapman is above average.

Vertical movement (inches)

Vertical movement vs. average (inches)

Horizontal movement (inches)

Horizontal movement vs. average (inches)

35.3

1.9

2.4

-1.9

The main movement of a splitter is vertical, so while he does not have much horizontal movement, he is fourth in the entire league in vertical movement. And when you mix that in with his other pitches, you get a devastating arsenal:

https://twitter.com/PitchingNinja/status/1385566721797500928?s=20 Each of his pitches moves in a different direction and they range from 85-100 MPH. Chapman is no longer a young ‘un at age 33 but he is throwing harder than he has in the past few years, and his splitter makes him one of the most lethal relievers in the game.