Breaking Down the Unique Changeup That Helped Kevin Herget Dominate the White Sox

With the Brewers having already secured a series win over the White Sox and a three-game series with the Phillies starting the following night, Pat Murphy stayed away from his high-leverage relievers in Sunday’s getaway game. That left Kevin Herget and Enoli Paredes to protect a close lead over the final four innings.

The duo, who have spent most of the season pitching at Triple-A Nashville, answered the call with scoreless appearances. Herget earned his first big-league hold, and Paredes notched his first save. The former’s outing was the more eye-opening, though.

Herget retired six hitters in order in the sixth and seventh innings, five via strikeout. He returned for the eighth and threw eight straight balls for a pair of walks, but Paredes escaped the jam--with help from Christian Yelich, who gunned down a tagging Tommy Pham at the plate for an inning-ending double play.

He ran out of gas at the end, but Herget’s outing was still impressive, even if it came against the worst lineup in baseball.

The 33-year-old dominated, thanks in large part to his changeup.

Eleven of Herget’s 31 pitches were changeups, making it his most-used pitch of the afternoon. That’s nothing new for the veteran. Of the pitches he’s thrown in his career that have been captured by pitch-tracking technology, 35.4% have been changeups.

“The changeup’s always been my pitch,” he said after the outing. “I’ve always had a really good changeup.”

It was great on Sunday. The changeup accounted for all three whiffs Herget recorded. The White Sox failed to put it in play even once, out of six swings. It’s a unique changeup, too.

The pitch has averaged 17.2 inches of arm-side run, which ranks in the 92nd percentile among pitchers who have thrown at least 30 changeups this season. Herget showcased even more movement on Sunday, maxing out at 22 inches of lateral movement on this changeup to strike out Oscar Colás.

Many pitchers throw straight changeups. In addition to reducing velocity, they strive to dampen spin and induced vertical break on the pitch, to create late drop that separates it from their fastball.

Herget throws a less prevalent kind of changeup. It averages 12.5 inches of induced vertical break, far above the league average of 5.3 inches. That’s less observed drop than the typical offspeed pitch.

“I would classify it as a carry, horizontal changeup for the most part,” he said. “My mindset has always been that if I get on the side of the ball and I rip through it, I don’t really care how much it spins. I’m trying to get a change of speed and some horizontal [movement] to it to get that separation.”

When throwing the changeup, Herget orients the ball in his hand like a four-seam fastball. Instead of staying behind the ball to generate backspin, his goal is to pronate and make it move laterally by producing as much sidespin as possible.

“I want to cut it in half and spin it as much as I can, so I’m moving my hand as fast as I can,” he explained. “I’m just trying to get the force away from the back side of the ball and through the side of the ball.”

Herget’s changeup spins at an average of 2,128 rpm, which ranks in the 88th percentile of changeups. It usually spins (from his perspective) toward 2 o’clock on a figurative clock, meaning it’s spinning sideways to his arm side.

The pitch has a 99% active spin rate, meaning that almost all of the sidespin Herget generates contributes to its plus horizontal movement. That spin is even more impressive with added context.

Spin and velocity are often correlated. The harder a pitcher throws a ball, the faster it will spin. Conversely, a slower pitch typically spins at a lower rate.

As the graph below illustrates, Herget has one of baseball’s higher changeup spin rates, despite the pitch’s low-80s velocity residing near the bottom of the league. This is what he’s talking about when he speaks of ripping the ball.

Herget also gets around the ball, with an arm slot that typically is not conducive to pronating. It’s typically easier to sidespin a ball with a lower release slot, but he has an over-the-top delivery. Herget’s release height is roughly five inches higher than the MLB average, despite his below-average 5-foot-10-inch stature.

Once again, Herget stands out. Few pitchers generate the sidespin and lateral movement he does on a changeup from a higher slot. That downward delivery also helps create a perception that his changeup is dropping more than it is as it approaches the plate.

If you’ve gotten lost in the technical jargon, the crux of Herget’s changeup is that it behaves much differently than offspeed pitches most hitters are used to seeing. In some ways, it’s a (far less extreme) version of Devin Williams’s changeup. Williams sidespins the ball from a lower release slot and generates vastly more spin and break, but the approach for making the ball move is similar.

Another commonality with Williams’s changeup is that it’s not a matchup-based asset. Whereas most pitches use their changeups primarily against opposite-handed batters, Herget’s side-spinner remains integral to his pitch mix against right-handers.

“I learned that, when I was in Double-A a bunch of years ago, using it to both hitters was successful,” he said, adding that the horizontal movement has sometimes made it even more effective against righties than lefties. To speak very generally, that's right: horizontal movement drives pitch efficacy to same-handed batters, more than to opposite-handed ones. Vertical movement tends to be the difference-maker for lefty batters, from a righty like Herget.

Herget’s changeup is a legitimately robust pitch, and leaning on it to the extreme (as Williams does) is probably his best path to success. Whether it’s enough to yield consistent results remains to be seen, but he is already the latest example of a minor Brewers acquisition making his presence felt in a positive way on at least one occasion.