The Yankees' super bullpen has arrived as intended

New York relies on a closing quartet of Chapman, Britton, Kahnle and Ottavino
Aroldis Chapman has 11 saves and a 2.16 ERA in 16 2/3 innings over 18 appearances. (AP)

Aroldis Chapman has 11 saves and a 2.04 ERA in 17 2/3 innings over 19 appearances. (AP)
For most teams, a starter going just five innings and handing a narrow lead to the bullpen is akin to walking on eggshells.
The Yankees, with their super bullpen in tow, are not most teams.
After a slow start -- at least for them -- the Bombers' relief corps have transformed once again into a lineup-wrecking machine. The quartet of Aroldis Chapman, Zack Britton, Adam Ottavino and Tommy Kahnle has effectively shortened games and given manager Aaron Boone plenty of options to finish out games.
The 2018 Yankees had the best bullpen of all-time based on FanGraphs' WAR. The 2019 version isn't quite at the same pace, but it's not far off. This year's bullpen has been worth 2.6 WAR, tied for first in baseball with the Rays while throwing 43 2/3 fewer innings than their counterparts in Tampa.
FanGraphs' pitching WAR relies significantly on peripherals -- strikeouts, walks and home runs -- and the Yankees have been solid in each category -- though their strikeout numbers are the best in baseball.
The Yankees have 201 strikeouts in 160 1/3 relief innings and lead MLB with a 29.4 percent strikeout rate. The group is also first in K-BB rate. In May, moreover, New York's relievers have reached a new level, striking out a third of batters faced.
How are the Yankees doing this? Well, the aforementioned quartet has an established hierarchy that's given Boone a blueprint to finishing games. They've been integral to keeping the team afloat amid a flurry of injuries to key contributors.
Finishing games, Chapman has seen his velocity tick back up above the century mark. At the same time, he's found his command while continuing to work in his slider more. The flame-throwing southpaw has thrown the ball in the strike zone more often and also induced more swings on pitches out of the zone.
In the eighth inning, Britton looks like his pre-injury self with an explosive sinker. He's also taken the new 'K' in his name seriously: His strikeout rate is at its highest level since 2016, and he's improved his walk rate.
That leaves Ottavino and Kahnle in the sixth and seventh innings for Boone to sort out as he sees fit. How do you differentiate between two hard-throwing right-handers? Well, Kahnle's changeup has him working as an unexpected lefty-specialist.
With his fastball velocity back near its 2017 peak, Kahnle's been able to keep hitters honest, and he's dominated lefties by going to his change. In 19 at-bats ending with a changeup, the righty has allowed just one hit while striking out 12 and walking two. Overall, he has a 1.50 ERA and has struck out 35.2 percent of batters faced.
Meanwhile, Ottavino has arguably been the Yankees' best reliever. Boone has typically used him as a fireman in the middle-to-late innings against righty-heavy portions of opposing lineups. As the sidekick to Kahnle, he's held righties to a .130/.322/.196 batting line.
American League opponents have seen Ottavino rise to the occasion consistently with his wipeout slider. Batters are 0-for-10 with seven strikeouts against him with runners in scoring position and two outs. Even former MVP Buster Posey and wunderkind Austin Meadows know this all too well.

Funny enough, the Yankees have been without arguably their top two strikeout artists; Dellin Betances is out until at least June, while Chad Green spent a couple of weeks with Triple-A Scranton re-working his mechanics after a worrisome start to 2019.
The bullpen has benefited from a stabilized rotation this season, with breakout hurler Domingo German joining a veteran core. Recent injuries to Jonathan Loaisiga, Masahiro Tanaka and James Paxton will test the club's pitching depth and could increase the burden on the back-end of the bullpen.
Still, the super-charged pinstriped relievers look up to the task. Despite plenty of five-and-fly starts from German, J.A. Happ and others, the Yankees have still won 14 of their last 17 games decided by three runs or fewer.
Even if the names are somewhat shuffled, the Yankees' late-game options have worked as intended. Opposing teams that can't break through against the team's starters are forced into a video game with four equally difficult bosses to conquer. With more arms potentially on the horizon, the bullpen continues to set the Yankees apart.