The New York Yankees' bullpen, after posting the lowest ERA in the majors in 2023, is a very different group this season. Key players departed over the winter, replaced by relatively obscure newcomers, while others are out early with injuries. A decline would've made sense.

But the Yankees' relief corps is again among the best in the sport, with the second-highest Win Probability Added and second-best ERA in the majors. The anchor is the most prominent holdover: Clay Holmes, the only qualified reliever yet to surrender an earned run in 2024.

With the Yankees off to a 27-15 start, fueled in part by their standout bullpen, Holmes just might be the best closer in baseball.

"STUD -- all capital letters there," Yankees reliever Luke Weaver said.

Holmes, in his second full season as New York's closer, has registered 21 strikeouts with three walks in 17 innings and leads the American League with 12 saves. And ask anybody in the Yankees' clubhouse: Holmes' performance in Baltimore earlier this month is still a talker.

The Yankees, six outs from victory, were nursing a 2-0 lead after falling to the Orioles in the first two games of the four-game series. A third straight loss to their chief competition for the American League East would be as backbreaking as it gets on May 1. The first two Orioles reached base in the bottom of the frame. Moments later, with one out and the top of the Orioles' order looming, Yankees manager Aaron Boone summoned Holmes for a five-out save. What followed was an electric, eye-popping performance.

Holmes struck out Gunnar Henderson, named the American League Player of the Month two days later, with a pair of sharp sliders and a 97 mph sinker. He then whiffed Adley Rutschman, the Orioles' All-Star catcher, on two hard sinkers over the plate, followed by a slider that nearly dropped Rutschman to a knee. Crisis averted. Holmes then kept the middle of the Orioles' explosive lineup scoreless in the ninth to secure the victory.

"That's about as nasty as it gets," Orioles manager Brandon Hyde said after watching the display. "When you're throwing 97 mph bowling balls with a slider, it's going to be tough to score against."

Veteran catcher Jose Trevino was around for Holmes' All-Star season in 2022. He has caught some of Holmes' most dominant outings. But that was the best he has ever seen from the closer.

"And I told him that," Trevino said.

Now in his fourth season with the Yankees, Holmes has the second-highest ERA+ ever for a Yankees reliever with at least 160 appearances -- behind only Mariano Rivera. He was an All-Star in 2022, snatching the closer job from Aroldis Chapman midseason. He was effective again in 2023, his first full season in the role, with a 152 ERA+ in 66 appearances.

But he has been even better in 2024. And with Holmes starring at the back end, the Yankees' bullpen boasts a 2.69 ERA, trailing only the Cleveland Guardians, even after a near meltdown Sunday against the Tampa Bay Rays. All this despite the significant year-over-year turnover.

Michael King, the Yankees' shutdown multi-inning weapon last season, was traded as part of the package for Juan Soto. Wandy Peralta, their best left-hander in 2023, is also in San Diego, after signing a four-year deal with the Padres in free agency. The hard-throwing Jonathan Loáisiga underwent season-ending elbow surgery after three appearances last month. Tommy Kahnle, currently on a minor league rehab assignment, has yet to throw a pitch in the majors this year.

The Yankees acquired left-handers Caleb Ferguson and Victor González from the Dodgers during the offseason. They signed Dennis Santana, on his fourth team in four years, to a minor league deal. They converted Weaver, a 30-year-old former first-round pick, from starter to reliever.

Ian Hamilton, one of the few relievers from 2023 still on the roster, had allowed eight earned runs in 15 appearances over three seasons when he signed with the Yankees before the start of last season. The 28-year-old right-hander was a revelation, recording a 2.64 ERA with 69 strikeouts in 39 games.

"There's a lot of reassurance, of showing what we do can get people out all the time," Hamilton said of the Yankees' coaching staff. "It sounds ridiculous, but then [there's] the Yankee Effect. When you're in the bullpen here, you just want to perform, and you want to show off for the Yankees. It doesn't make it easy, but that motivation is like always here. There's always that drive."

Boone credited the Yankees' front office for its ability to identify undervalued arms and maximize their abilities. The expertise has produced bullpens that have finished in the top five in ERA over the past three seasons. Nobody embodies the organization's knack for bullpen construction better than Holmes.

The Yankees acquired the 6-foot-5 right-hander from the Pittsburgh Pirates in July 2021 for infielders Diego Castillo and Hoy Park. Holmes had a 4.93 ERA in 42 innings that season at the time of the trade. He owned a 5.57 career ERA over parts of four seasons. Nothing indicated dominance was around the corner.

"We feel like he's going to be a guy that is already very tough on righties," Boone said at the time, "but we feel like he has the stuff and the repertoire to go to another place."

The Yankees had Holmes ditch his curveball for a sweeper to complement his sinker and gyro slider. The sweeper, a slider with a bigger break, plays better against right-handed hitters. The gyro slider, a harder offering, is more effective against lefties. He allowed just five runs in 25 outings to close the regular season.

Three years later, Holmes has yet to give up a hit on either of his sliders while posting the second-highest ground ball rate (71.1%) among qualified relievers behind a devastating sinker averaging 96.3 mph. He has a 61.5% whiff rate on the 34 sweepers he has thrown -- all to righties -- with six strikeouts. His gyro slider ranks as the best slider in the majors, according to the stat Run Value/100 Pitches.

"A lot of it for me is nailing my direction," Holmes said. "I'm able to just move down the mound faster and I just think it helps my body move a little better. Just kind of knowing my lanes, the direction I need to get going. It's a product of me just moving down the mound better. It frees up my arm. The stuff moves from that."

Holmes' only blemish so far this season came after shortstop Anthony Volpe's error on a routine play led to three unearned runs in the 10th inning of a win over the Arizona Diamondbacks on April 3. On Friday, the Rays nearly ended his scoreless innings streak, but he escaped a bases-loaded jam with his third strikeout of the inning, closing out a 2-0 win and keeping his 0.00 ERA.

"Clay's pretty much the same person every day: Calm," Hamilton said. "He's ready to get put in the game pretty much any day. However many times it takes."