Since debuting for the Dodgers in 2019 sporting long, flaming red hair and an intimidating 6’6” body, Dustin May has employed a four-pitch mix with the potential to allow him to dominate in any given outing. He mixes high-90s sinkers and 4-seam fastballs, a low- to mid-90s cutter, and a mid 80s curveball which all employ high percentile spin rates compared to the rest of the league. Although at times he can make hitters look silly with his pitches, like with the strikeout of Manny Machado shown below, courtesy of Rob Friedman (@PitchingNinja), May hasn’t been able to consistently miss bats and rack up high strikeout totals until this year.
During 2020, in comparison to the rest of baseball, May’s whiff rate, or the percentage of misses he generates when a batter swings, was at the 7th percentile and his strikeout rate was at the 27th percentile. However, according to Baseball Savant, May’s rankings so far this season shot up to the 78th percentile for whiff rate and the 93rd percentile for strikeout rate. In other terms, May has faced 86 batters so far in 2021, and he has struck out 32 of them, already matching his total from the cup of coffee he spent in the Majors in 2019. So, the obvious question is, how has May been able to miss bats at the best rate in his young career so far?
His pitches mostly have the same velocities and similar spin rates as they did in 2020, but it’s his pitch usage and movement on some of those pitches that’s changed. Although his primary pitch continues to be his powerful sinker, he’s decreased the percentage he throws this pitch from 51.4% to 40.8%, and he’s changed up the usage of his secondary pitches, decreasing his cutter percentage from 24.6% to 18.2%, and increasing both his curveball and 4-seam fastball from 13.4% to 22.9% and 5.5% to 18.2% respectively. As May’s racked up more innings in the Majors, he’s becoming more and more comfortable controlling and going to his effective secondary pitches, therefore keeping batters guessing more than before about what pitch he’s going to throw.
Individually, two pitches that deserve a closer look are May’s cutter and curveball. Last year, May’s cutter was his go-to secondary pitch, as he used it about a fourth of the time, and although he’s decreased its usage, that’s not due to a lack of effectiveness. In fact, the Whiff% on that pitch has more than doubled from 26% last year to 56.7% this year. This pitch now acts as a compliment to his much straighter 4-seam fastball as he uses these pitches the same amount of time. He’s been able to tunnel them well together, with the cutter being a little slower than the 4-seam fastball but having later break towards the glove side.
Unfortunately for the cutter (and the rest of MLB), May’s curveball has developed into such a dominant secondary pitch that his other offerings take a backseat to it. Evident by @PitchingNinja GIFs on Twitter like these:
The whiff rate on May’s curveball has increased from 38.8% to 46.2%, and the horizontal break has increased on it from 10 inches to 15 inches. Without altering his spin rate, velocity, or delivery, May has been able to change the shape of the break of his curveball this season. An explanation as to why his curveball has changed so drastically is an idea first publicly theorized by Utah State University Professor Barton Smith (@magnusPI) called seam-shifted wake. This is the idea that changing the orientation of the seams of a baseball can alter the movement of the ball in air. It’s a relatively new study of a baseball’s aerodynamics, and while I’m not a physicist who can explain the intricacies of how it works, May’s teammate, Trevor Bauer, has been at the front of understanding pitch design and it wouldn’t be unlikely that he’s shared his knowledge with his fellow Dodgers pitchers. This new area of study might also help explain how May is generating a higher percentage of swings and misses on his cutter. Here’s a graph showing the difference in May’s pitch movement direction and distance from 2020 and 2021.
As shown above, the yellow dots representing May’s curveball have shifted more horizontally towards nine o’clock this year, about 20 to 30 degrees, due to his new pitch design. In total, it appears that the combination of growing experience and confidence in his secondary pitches, changes in pitch usage, and the leveraging of seam-shifted wake effects has allowed May to start maximizing the deadly potential in his pitch arsenal. With a 2.53 ERA, 32 strikeouts in 21.1 innings, a 0.938 WHIP, and a .188 batting average against so far in 2021, it seems as though Dustin May has taken a step forward in the majors. Oh, and he’s only 23. Good luck to the rest of the league if he continues on this path and continues to improve.
Featured Photo: Mark J. Terrill / Associated Press