For years, teammates have asked Devin Williams to teach them his changeup, a pitch so unusual and dominant it has its own nickname. Williams always helps. They just never get "The Airbender" right.

"I haven't seen anyone replicate it," Williams said.

Powered by The Airbender, Williams has established himself as one of the premier relievers in baseball since breaking into the majors in 2019. He has been so good that the Milwaukee Brewers, keeping with their frugal roster-building tactics, traded Williams to the New York Yankees last month for left-hander Nestor Cortes and prospect Caleb Durbin before he inevitably would become too expensive in free agency next winter.

So, for one season, at least, Williams will follow in the footsteps of another Yankees closer who perplexed hitters with one pitch: Mariano Rivera.

"Those are big shoes to fill," Williams said of Rivera, whose signature cutter helped him become the first player voted unanimously to the Hall of Fame. "I feel he kind of ruined it for everybody else. I mean, after him, it's hard to live up to those expectations. But at the end of the day, I can only be me."

Being himself has been more than good enough for the 30-year-old Williams. The right-hander won the 2020 National League Rookie of the Year Award with a 0.33 ERA in 22 games as the Brewers' primary setup man during the COVID-shortened campaign. He was an All-Star in 2022 and 2023, his first full season as a closer.

Last season, after missing the first four months with stress fractures in his back, he posted a 1.25 ERA with 14 saves in 15 opportunities across 22 appearances. His 40.8% strikeout rate since 2020 ranks second in the majors among relievers. His 1.70 ERA is also second. His .144 batting average against ranks first.

"Obviously, he's one of the best in the league, if not the best," Yankees pitching coach Matt Blake said.

For Williams, it all starts with The Airbender. Williams grips it like a changeup and its 84-mph average velocity plays off his fastball like a changeup. But it's a changeup with an exceptionally high spin rate that breaks to his arm side -- opposite from the typical changeup -- making it resemble a screwball or a left-hander's sweeping slider. It is without precedent.

"It's not anything to do with the grip," Williams said. "The grip is nothing special. That's why I think it's funny when people are like, 'Oh, don't give it away.' This is the most basic changeup grip they teach you when you're 8 years old."

Williams said his changeup is so different for two reasons: His elite extension, which ranked in the 98th percentile in 2024, and a singular ability to pronate his wrist.

"It's the way my wrist works, the way I'm able to manipulate the ball is something unique, uniquely me," Williams said. "It allows me to throw my changeup the way I throw it. I'm a really good pronator, not supinator. That's why my slider sucked. You need to get on the other side of the ball. I'm not good at that. I'm good at turning it over."

Williams did, however, modify his changeup grip to unearth the weapon. Entering 2019, Williams was a struggling minor league starter with a solid changeup, two years removed from Tommy John surgery. He was one year from reaching free agency, from perhaps seeing his career come to an end and going to college to play soccer.

That spring, seeking more movement, he altered his changeup grip from a two-seam to a four-seam, circle change grip. He first threw it during a live batting practice session to Trent Grisham, then a Brewers prospect. Grisham, now with the Yankees, told Williams the spin difference was noticeable. Williams stuck with it.

A starter through spring training, Williams was sent to Double-A as a reliever to begin the season. The demotion sparked desperation, and Williams decided to throw harder than ever, reaching back to lift his fastball into the high 90s. He was in the majors by August. But it wasn't until the COVID shutdown in 2020 -- when he realized spinning the ball more and dropping the velocity from high-80s to mid-80s created more movement -- that his changeup reached another level.

"I took that into the season and at summer camp I'm facing my own teammates," Williams said. "And Jedd Gyorko, I threw him one, and he swung and missed and he was just like, What is that? I've never seen [anything] like that. That gave me confidence and we just ran with it. And I literally started throwing it all the time."

Coincidentally, Williams said the closest changeup he's seen to his belongs to Luke Weaver, whose emergence as a shutdown reliever in 2024 was crucial in the Yankees reaching the World Series. Williams happened to be in New York when the Yankees and Los Angeles Dodgers played in the Fall Classic. He was on his annual autumn vacation after the Brewers were eliminated from the postseason. Past trips have taken him all over Europe: London, Paris, Dublin, Amsterdam, Munich, Dortmund, with a soccer game invariably on his itinerary.

This time, he was in New York. He explored the city for 10 days. Instead of soccer, he watched the World Series from a bar. He shopped. He ate good food. He absorbed the city's energy.

"I'm a city guy," Williams said. "I love to explore cities. I like to immerse myself in the culture. I want to be like a normal, everyday person. You guys like bacon, egg and cheese? All right, I'm getting a bacon, egg and cheese."

Less than two months later, as part of a series of moves executed in their pivot from Juan Soto's decision to sign with the crosstown Mets, the Yankees added Williams. On Thursday, Williams settled for $8.6 million to avoid arbitration.

He'll partner with Weaver to create one of the best bullpen back ends in baseball -- in hopes of helping the Yankees win their first championship since Rivera was dominating hitters with his cutter.