For the season, the Yankees rank top five in bullpen ERA (3.49), FIP (3.66) and fWAR (6.5). This may surprise some considering the struggles of Aroldis Chapman and Zack Britton at the back-end of New York’s bullpen. In total, Chapman and Britton have a combined 4.33 ERA in 62.1 innings, which of course is less than ideal. It’s hard to imagine many relief units being better than the Yankees’ if their two most expensive relievers were not struggling the way they have.
Instead, it has been Jonathan Loaisiga’s breakout this season that has lifted the group. In 66.2 innings, Loaisiga owns a 2.16 ERA, 2.41 FIP, and he leads all qualified relievers with a 2.4 fWAR. He has been outstanding, and a few tweaks from last season are responsible for this seismic step froward.
Increased Sinker Usage
There’s arguably no bigger cause for the improvement we’ve seen from Jonathan Loaisiga this year than his increased sinker usage. Loaisiga is throwing his sinker 54.4% of the time in 2021, up nearly 30% from his 24.6% usage rate last season. While Loaisiga doesn’t generate a ton of swing and miss (8.9 K/9), his sinker helps induce an elite amount of soft contact on the ground. For the season, Loaisiga ranks in the 99th percentile in average exit velocity (84.0 MPH) and hard hit rate (23.8%). Additionally, his 61.5% ground ball rate is eighth out of 158 qualified relievers. As a result, he’s allowed only two home runs in 66.2 innings.
Overall, Loaisiga’s sinker has a -12 run value, per Baseball Savant, making it one of the 35 most valuable pitches in baseball this season. Hitters have a .212 xBA and .275 xSLG against the offering, and it has limited opponents to a 27.7% hard hit rate. The Yankees have made a team-wide change to throw more sinkers under second-year pitching coach Matt Blake, and arguably no one has benefitted from it more than Loaisiga.
Improved Command and Control
As was already highlighted, Loaisiga isn’t a pitcher that racks up a ton of strikeouts. More often than not, he pitches to contact (ranks 106th out of 158 qualified relievers in K/9). For that reason, it’s crucial that his command is pinpoint. Loaisiga has lived on the corners and off the plate this season. His 37% chase rate ranks in the top one percent of all pitchers. That’s largely thanks to his wipeout curveball, which has produced a 47.5% whiff rate. Loaisiga is throwing it 22.7% of the time this year, and hitters have a .111 xBA and .130 xSLG against the curve. It has been beyond elite as a secondary offering.
On top of the leap forward in command, the young righty has also greatly improved his control. Over the previous two seasons, Loaisiga was really held back by walks. In 2019 and 2020, Loaisiga allowed 24 free-passes in 54.2 innings (3.9 BB/9). This year, Loaisiga has cut that down to 15 walks in 66.2 innings, and is 20th among qualified relievers with a 2.0 BB/9. Once again, it’s important to keep runners off the bases when you’re pitching to contact, and Loaisiga has done just that.
To the Yankees’ credit, they’ve used Loaisiga in a perfect role this season. Instead of locking him into a permanent one-inning, setup job, they’ve moved him around based on the most high-leverage spots of each game. The 26-year-old righty leads the team with 20.1 high-leverage innings pitched, ahead of both Aroldis Chapman (18.2 IP) and Chad Green (16.2 IP).
Loaisiga has also been asked to get more than three outs in 23 of his 53 appearances, something that you can expect to see more of down the stretch and in the postseason. If the Yankees are going to make noise in October, they’ll likely need Loaisiga to replicate the type of performance the 2016 Cleveland Indians got from Andrew Miller. Time will tell if he’s up to the task.