Slider has prevented any slide by Aroldis Chapman

Aroldis Chapman sometimes wins the battle before he even throws a pitch.

Long and broad shouldered, his body is naturally imposing, and when he bursts out of the bullpen, the bill of his hat is pulled low, casting a shadow over his eyes. He has that old, imposing-sounding nickname — the Cuban Missile — and when he’s at Yankee Stadium, his name erupts into flames on the scoreboard. Rage against the Machine blares over the sound system, and the urgent guitar riffs serve as a sort of warning for whoever has the unhappy assignment of hitting against him first.

It may be a little kitschy, but for years, it’s also been accurate: Chapman throws very, very hard. But these days, it doesn’t always quite tell the whole story.

The Yankees’ closer still gasses it up plenty — he’s dialed it up to and past 101 mph 47 times this year — but that’s not as common a sight as it used to be. His average fastball velocity is down, he’s 31 years old, and he’s playing a position known for meteoric rises and sudden, career-ending crashes.

All those things point to inevitable decline … except for the numbers.

During the last two years, Chapman has succeeded where other fireballers have fizzled. His 2.21 ERA this season is the best it’s been since 2016 and he finished with 37 saves, on par with his shockingly dominant early years with the Reds. He struck out 85 in 57 innings.

His peripheral stats, meanwhile, show a player who has rebounded by going in a different direction. Chapman is adapting by way of his slider.

“You know, I’m not 20 anymore,” he said through an interpreter. “As your career keeps going, you also have to make adjustments. At some point, speed will go down, and you also have to develop other pitches to be effective.”

But rather than filling him with some sort of existential dread, the inevitable nature of aging has given Chapman a road map of sorts. It’s one that very much has benefited the Yankees, who have the luxury of a shutdown bullpen without some of the normal agita associated with the unit.

“It’s not hard [to come to terms with an aging arm],” Chapman said. “It’s something that you plan in the offseason. You have an idea what you want to do, you work on that, you work on it during the offseason, you work on it during practice and eventually, you bring it into the game.”

Fully 31.1 percent of the pitches he has thrown this season have been sliders — an increase of more than 15 percentage points since 2016. His fastball velocity is down to 98.3 mph, but his sharp-breaking slider averages 85.4 mph, meaning that the batter needs to make a huge adjustment if he’s expecting the fastball. Even if his slider moves toward the middle of the plate – which it does fairly often – it’s still an extremely difficult pitch to hit, thanks to its late break.

“That’s become an elite pitch for him — a pitch that he can throw for strikes and a swing-and-miss pitch for him – to go along with still a great fastball,” Aaron Boone said of the slider. “I think just the unique combination of fastball, slider and the trust in both of those pitches now has allowed him to continue to be great in probably what is the middle of his career now.”

That’s reflected well enough in some of the categories Chapman used to dominate. He no longer leads the majors in fastest pitches thrown (that honor goes to the Cardinals’ Jordan Hicks) and doesn’t have the most 100-mph- plus pitches in the majors this year. In fact, Chapman isn’t even in the top three fastest pitches thrown, having maxed out this year at 102.7 mph.

He has compensated by fine-tuning his delivery, which is deceptive enough to keep hitters off kilter. The majority of his fastballs to righthanded hitters nick the high outside corner. His sliders take the same trajectory until the batter already has committed. Many end up about knee high, in the middle of the zone.

“It’s the best it’s ever been for me in my career,” Chapman said of his slider. “I think a reason for that is because I worked a lot on it. I worked a lot on it during practice, I’ve used it a lot during games. Before, I used to use my fastball way more and now I use the slider more, so I’m more confident using it and I’m having better results with it.”

So even though his fastball has gotten slower by about 1 mph every year since 2016, Chapman doesn’t wring his hands as much as a fan might. Instead, Boone noted, he controls what he can control.

“He’s really talented and physically takes really good care of himself,” Boone said. “He really, really works hard on keeping himself — he’s obviously a physically imposing, impressive person, but he works really hard to keep that. I think his [delivery] is unique and really special and it’s probably something that’s allowed him to remain healthy as well.”

Certainly, the development of a plus breaking ball could help his arm stay healthier longer. That’s of keen interest to the Yankees, who signed him to a five-year contract that will end just before Chapman turns 34. That’s also of interest to Chapman, who can opt out after this year. His arm and adaptability could net him a tidy fortune, depending on how much teams are willing to invest in closers.

“There’s no reason to say five, six years from now, if he’s only throwing 95, he can’t be an elite closer,” bullpen coach Mike Harkey said. “Going forward, it’ll be more about command than velocity, and I think he’ll be fine if he has to do that.”

The question is, how much is Chapman willing to bet that he can keep adapting to an aging body?

“I want to play here for more years, for sure,” he said when asked about his future with the Yankees. “But the baseball business has been changing a lot and you never know. You never know how things can go.”

He’s as much an example of that as anyone.

By Laura Albanese

laura.albanese@newsday.com@AlbaneseLaura

Laura Albanese is the Mets beat writer for Newsday. She's been covering MLB since 2014 after starting at Newsday as an intern seven years earlier.