The Yankees’ Cory Gearrin experiment

The Yankees claimed Cory Gearrin off waivers from the Seattle Mariners on August 23, adding the 33-year-old right-hander to their bullpen. He’s only been with the team for two weeks, but you probably already know him as the pitcher with the unorthodox toe tap or the guy who looks like Mike Mussina. Gearrin brought a respectable 3.92 ERA with him to New York, but the Yankees pounced on Gearrin because they saw potential for more upside. The Yankees acquired him because they saw a potential contributor for at least the final stretch of the regular season.

“Excited to get him. A guy that’s really tough on right-handed hitters,” Aaron Boone said when the Yankees acquired Gearrin. Hopefully there’s some things that we could do with him that help him improve on his game even a little bit more. But we feel like he’s a guy that, in the month of September as we expand (rosters), can be a guy that, there are some lanes in the course of a game that he can be really good.”

The question remained, what improvements did the Yankees want to help Gearrin make before he hits free agency at the end of the season? Gearrin is primarily known as a sinkerballer, and there was speculation that the Yankees were enamored by his league leading horizontal sinker movement. If his first handful of appearances are any indication, the Yankees have encouraged Gearrin to take advantage of his slider, especially against right-handed hitters.

Gearrin has pitched at least 46 innings each of the past four seasons so there’s not a lack of historical data to consider. In each of those seasons, right-handed batters have posted an expected batting average below .200 against his slider. While the movement on his slider is nothing special, he does rank 22nd in MLB in average slider spin rate, among pitchers with a minimum of 250 pitches (Statcast). In July, Gearrin’s pitch mix was 45.6% sinkers and 27.9% sliders. In five appearances for New York, Gearrin is throwing his slider on more than 43% of total pitches and 62.9% of pitches to right-handers. The Yankees are known as a slider-happy organization and Gearrin appears to be their next experiment.

It’s a small sample, but the results for Gearrin’s slider haven’t been great since he joined New York. Opponents are 5-for-12 against his slider and his best outing as a Yankee came in extra innings against Oakland, an outing in which he threw only 23.8% sliders. What’s especially interesting is that Gearrin featured his slider heavily over the first two months of the season and posted a solid 3.63 ERA. Then he switched to a sinker-heavy mix in June and had his worst month, but didn’t revert back to his slider in the coming months before being waived.

It’s too early to say if the Yankees’ experiment with Gearrin is a success or a failure, but there was little-to-no risk in acquiring the veteran right-hander. His history of success with a potentially under utilized slider could make him an intriguing option against right-handers during the stretch run. If the Bombers like what they see in Gearrin’s trial run, he could even find a role in the bullpen next season, although their tremendous depth makes him a long shot.