Emergence of Aroldis Chapman's slider could be pivotal
With Aroldis Chapman, it's all relative.
We can talk about his four-seam fastball velocity dipping through the first month and change of the season. This is true. It has been true. In 2017, he averaged 100 MPH; in 2018, 98.7 MPH; to open 2019, 97.3. That's certainly a difference and it's absolutely worth noting, but a rich man can lose a lot of cash before he starts begging. It should be noted that Chapman's still fine in the fastball department, as evidenced by the.281 xwOBA against his 2019 heater.
So, then, don't take it as a matter of crisis that the Yankees closer is throwing his slider more. He's 31. Time spares no man, and he's set a level of performance that both he, the team and the fans all want him to maintain. There's a certain burden to excellence. Plus, how long can any human cut loose 100 MPH fastballs without degradation? It has a cost.
Fortunately, the slider is special.
First, the fancy stats: hitters are whiffing about 48 percent of the time against the slider in 2019, down a bit from last year's 62 percent. I expect the 2019 figure will climb, but remember the lead. It's all relative with a reliever this good. Hitters striking out at a nearly 50 percent clip against your breaking ball is excellent.
For a bit of context, consider Adam Ottavino. The new Yankee has a physics-bending breaking ball; it whiffs at a 44.4 percent clip. Chapman's slider is getting more whiffs than Josh Hader's frisbee, and I'm pretty sure Hader is an alien. Now, I'm not saying Chapman's slider is a better pitch than theirs, but it's become pretty nasty.
Next, the gif (courtesy of the wonderful Rob Friedman, the Pitching Ninja) of a slider Chapman unleashed last August:
https://twitter.com/PitchingNinja/status/1028375642990104576
Look at the way Shin-Soo Choo reacts to it. Choo is one of the more disciplined hitters in baseball, even in his decline, and he absolutely flinches at Chapman's slider out of the hand. That's because the slider is tunneled with the fastball, meaning both pitches look the same most of the way to the plate. It's a real picnic to be a big league hitter. It'd be even worse for the batter if Chapman had a more consistent feel for the strike zone (although this year, small sample size alert aside, his walk rate is lower than usual).
Chapman's usage rates are changing as he ages. If you dig into his past, particularly with the Cincinnati Reds, he pumped fastballs over and over. Hardly takes an expert to figure out why: Chapman's fastball in those days was extremely hard to hit. (It still is.) For the first time ever, though, Chapman has turned to his slider more than 30 percent of the time, indicative of his softening velocity and also his trust in the breaking ball. It's a hell of an offering and Chapman is well aware he'll need it as the innings pile up.
That's an encouraging development for the Yankees, who are committed to the Cuban relief ace through the 2021 season. Hard to say with his injury issues whether Chapman will be excellent for that long, of course, but for this season, with Dellin Betances out hurt and Zack Britton seemingly unlikely to regain his astonishing 2016 form, Chapman is a rock for Aaron Boone to rely on at the end of games. Tommy Kahnle has been great and Ottavino is reliable, but Chapman is still the man.
Adam Adkins also writes about baseball at AdkinsOnSports.com. His most recent Ode to a Pitcher breakdown covered Tyler Glasnow.