The New Pitches of Trevor May and Tyler Duffey

There is no greater example of that phenomenon than the two-headed set-up monster that developed in the bullpen during the second half: Trevor May and Tyler Duffey. Those two benefited tremendously from tinkering with their stuff on their own, readily accepting the feedback they got from coaches and front-office personnel, and steadily increasing their commitment to their adjustments over time.

For most of his career, May has used a changeup and a curveball, in addition to his four-seam fastball. The curve was the pitch that came naturally to him, based on his arm slot and mechanical signature. He also tried a cutter-style slider at various points during his career, but struggled to make it an effective offering.

Then, while playing catch with Ryne Harper one day, he tried something new: He started gripping his slider virtually the same way he grips his curve, with his index finger curled and flexed into a spike and the middle finger extended along the seam of the ball. He still used slider-like wrist action at release and threw the pitch harder than he throws his curve, but what he essentially found that day was a new slider, a pitch with the vertical depth and bat-missing potential his previous sliders had lacked.

It took quite a while, though, for the pitch to really become a weapon for him. In an interview just after Memorial Day, May said he had discovered the new grip and its potential while the team was in Houston in late April. In the five weeks since, though, he’d only taken his new toy out for a spin in games some 32 times, and there was a three-week stretch immediately after the grip change during which he didn’t throw the slider at all.

That changed. From mid-July through the end of August, May threw the slider 35 times and threw zero curveballs. As he said in an interview in May, it was not a matter of finding the new grip and receiving the Twins’ enthusiastic reports on it (it had a considerably higher spin rate, and moved from a pitch that stayed almost on plane with his fastball to one that dived more than 90 percent of the other sliders throughout the game), but of mastering it. He talked about feeling his way from being able to throw the pitch for a strike or for a ball, and to throw it as a ball that would start out looking like a strike, but end up being a ball.

By the end of the season, May’s breaking balls had melded into one pitch, probably more properly called a curve, but with much more power than the curve he was throwing early in the season. He became more fastball-heavy, setting hitters up with high-spin heaters at the top of the zone, and caught opponents badly off balance when he then threw his changeup or breaking balls.

Duffey’s breaking ball underwent a similar transformation, though no technical name change. At the start of the season, his average curveball came in at 81.1 miles per hour, with about 8.5 inches more vertical drop than would be expected without the spin he imparted. Each month, those numbers moved slightly, and always in the same direction. By September, his average curve sat at 83.9 miles per hour, and it was dropping just 6.3 inches. The pitch also had less horizontal movement, although by a very slim margin, by the end of the season. He’d graduated from having a loopy hook, flush with movement but light on deception, to firing in a power hook that fooled hitters more by mimicking his fastball better.

Like May, Duffey was working constantly to improve the pitch on which Wes Johnson had given him feedback and information. It wasn’t just about acknowledging the opportunity to make a change, or about actually making it, but about feeling confident in it. May and Duffey each became more mechanically consistent, found more consistent power and command, and were able to engineer more effective breaking balls.

It just took time. Early on, their reputations and apparent unreliability had fans of the otherwise exceptional Twins wringing their hands. By the final two months, they were (arguably) the most effective set-up tandem in the majors, papering over other cracks that appeared in the pitching staff.

Every pitcher is different. That’s a key fact in understanding and implementing important changes for pitchers as an organization. May’s experience demonstrates that there’s a slider in almost every arm, and Duffey’s maturation shows how even a pitcher with a relatively long, spotty track record and an obvious deficiency can easily overcome that in this age of information and technology.

What both also show, however, is that even moments of epiphany don’t lend themselves to instant turnarounds. Finding a new grip and unlocking better spin characteristics are important breakthroughs, but shouldn’t be expected to produce immediate changes in results, or even approaches within games. It’s important to listen to what the Twins’ coaching staff and pitchers say about what’s going on behind the scenes, because an adjustment already made (in one sense) might still be in its incubation period, waiting to pay dividends if the player keeps buying in and the team keeps showing faith throughout the process.