What Justin Wilson brings to the Yankees’ bullpen

With the reports locked in that Justin Wilson is now a Yankee, New York’s bullpen appears to be pretty well set. Wilson becomes the third lefty in the relief corps, joining Zack Britton and Aroldis Chapman, and a change in his pitch usage over the last two seasons highlights how we can expect him to go after hitters in pinstripes.

Wilson is effectively a two-pitch pitcher, throwing his four-seam and cutter about 93-94 percent of the time over the past two years — a significant change from previous seasons, where the former dominated every plate appearance. The two pitches play off each other well, and the cut really works to hide some of the weaknesses of Wilson’s fastball. There’s nothing wrong with his four-seamer per se; it’ll average around 95 mph, with a mediocre spin rate that leaves it relatively middle-of-the-road in terms of effectiveness.

The four-seamer becomes especially handy when Wilson is throwing his cutter 40 percent of the time. The cutter moves a lot, as evidenced by 2019, when Wilson’s cutter broke 3.4 inches horizontally on average, or about 175 percent more horizontal movement than an average cutter. Throwing from the left side means that the ball breaks in on a right-handed hitter, neutralizing some of the natural platoon advantage. You can see the way each pitch plays off each other in this at-bat against Kurt Suzuki last year:

That called strike two is the four-seam, up and in on Suzuki. He benefits from a generous call, sure, but it’s the follow-up one pitch later — a cutter bearing about three inches lower — that really makes the four-seam work. Suzuki just saw a pure fastball inside that he couldn’t pull the trigger on, and now he gets a pitch that looks like a meatball, until those last 15 feet, when it breaks down and in. Suzuki is already swinging at that point, and he harmlessly knocked the ball foul. If he doesn’t swing, Wilson’s control is good enough to keep that pitch in the strike zone, and Kurt would be down looking.

It’s this interplay between the four-seam and cut that keeps hitters so off-balance, just like that sequence to Suzuki. Since both pitches behave in similar ways until the cutter breaks, hitters are largely reduced to guessing, speeding up their swings, and making weak contact. In fact, Wilson’s been one of the best in baseball at suppressing contact over the past two years, in the top, err, bottom 10 percent of baseball in both exit velocity and hard hit rate.

The two drawbacks to Wilson are his release point and control:

Here, with four seamers in red and cutters in brown, it’s evident that there is a certain level of demarcation between the two pitches. Part of this is a symptom of the pitches Wilson throws — release point plays a huge role in the horizontal movement of a pitch, so if you want a cutter to cut, it can’t be thrown over the top. However, a more disciplined hitter may be able to pick up on slightly different release points, being tipped off about the pitch.

Second, and perhaps more concerning, is control. I like to combine 2019 and 2020 stats for relievers just to try and get a better sample size picture, and of the 198 relievers who have thrown 50 innings over those two seasons, Wilson’s walk rate ranks in the 22nd percentile. Because he works inside to righties so much, he’s often at the mercy of umpire’s calls, and his stuff just isn’t dazzling enough to induce whiffs on pitches outside.

That walk rate has been what’s kept Wilson from being a truly elite reliever, and any Yankees fan that’s seen Aroldis Chapman lose the zone knows how difficult it can be to have a reliever who can’t throw strikes. Still, the pitch-to-contact approach is something that has worked well for the Yankees in the past — see Britton, Zack — and Wilson can be a nice complement to that in 2021.