Luis Severino’s changeup-heavy first start

Like many of his rotation counterparts, Luis Severino is an enigma. As a former top prospect, he possesses enormous upside. He has front of the rotation raw stuff. At the same time, his numerous drawbacks lead some to speculate that he ultimately belongs in the bullpen. Yankees fans and columnists alike seem divided on the issue. Take a cursory glance of Twitter and you will find no shortage of Severino debates. In fact, Pinstripe Alley addressed both views on the matter during the offseason.

I’m not going to relitigate the case for or against Severino the starting pitcher here. The Yankees made their decision. They remain committed to using him as a starter. Instead, I’m going to look at what Severino needs to do to achieve success in the rotation and measure his progress. It’s no secret either. His future ultimately hinges on the development and execution of a quality changeup.

Severino made his first start of the season on April 7th against the Orioles. The results weren’t dazzling or particularly memorable. He surrendered four runs over five innings. He allowed six hits, including a home run. On the plus side, he struck out six batters. That’s not necessarily a good performance, but it wasn’t the type of disastrous start that plagued his 2016 campaign.

On the surface level, it can best be described as ‘meh’. Upon closer review, however, Severino’s outing reveals a positive sign. Of his 89 pitches against the Orioles, Severino threw 14 changeups. That breaks down to 15.73% of his pitch count. A plot of the pitches is available thanks to Statcast.

That’s quite the improvement over the 8.83% of change pieces he threw last season. He didn’t waste any time throwing the pitch. He came right out of the gate with them. Of those 14 changeups, however, only five generated swings.

Just two of those resulted in swinging strikes. Two others came squarely into the danger zone, middle-middle where the off-speed pitch acts more like a batting practice fastball. There’s clearly some improvement in order. He needs to polish his location and create a downward plane, one that would bait hitters into swinging over the change piece. This is very much a pitch in development.

The fact that Severino is making an attempt to harness a changeup, however, bodes well for his future in the rotation. He understands the importance of the pitch and feels good throwing it. “I have a lot of confidence in the changeup,’’ Severino told the New York Post in February. “For me it’s my most important pitch. You can’t be a starter with two pitches, you need more than two pitches.” Severino notably trained under the watchful eyes of Pedro Martinez, himself a changeup master, over the offseason. It’s possible that the lesson stuck.

The Tampa Bay Rays have become famous for changeup development over the years. Neil Allen served as the pitching coach for the Rays Tripe-A affiliate Durham Bulls in 2007. He told Baseball Prospectus how the organizational changeup revolution came about.

“How it started was, ‘We want you to throw 10 to 15 percent changeups tonight.’ And so we’d go on percentages. It would come out as righty-on-righty sometimes to get to the percentage we wanted. We started seeing success left-on-left and right-on-right, and then we started feeding off it more and more.”

This should serve as the model for Severino. Develop confidence in the pitch by throwing it more. He should have a goal in mind regarding how many times he goes to the changeup. The number has to be fluid considering it’s a situational pitch for Severino. His fastball and slider will always serve as the out pitches. The 10-15% model makes the most sense. He’ll throw it just enough to keep batters guessing. It’s also reasonable to expect his changeup to increase in effectiveness the more the throws it. Practice makes perfect, after all.

Severino’s next outing comes on Thursday night against the Rays. It will be worth monitoring how often he goes to the changeup. Will he continue to go to it at a 10-15% rate? Or will he abandon the pitch when in favor of his comfort zone fastball and slider? Severino made it past the first checkpoint. He’s shown that he can grow and listen to coaching. Now it’s time to prove that the development is sustainable and double-down on the changeup.

Data courtesy of FanGraphs and Baseball Savant.