Do the Phillies rank atop the best bullpens in baseball?

The Philadelphia Phillies season didn’t start until April 7.

Yes, there were a group of 26 players wearing gray “Phillies” uniforms who looked like the Phillies, but they were merely imposters, holdovers until the real Phillies could arrive for the home opener against the Cincinnati Reds.

Since that date the Phillies are 10-7 with a plus-14 run differential. They’ve played exactly as one would expect for a team missing their two best hitters — Bryce Harper and Rhys Hoskins — and the best number three starter in baseball in Ranger Suárez.

Chiefly, the bullpen has also performed as expected since the real Phillies arrived. During the six fake first games of the season, the bullpen was dead last in National League ERA (8.44). Nearly every reliever save Jose Alvarado saw their talent removed in a situation not dissimilar to the Monstars in Space Jam. Since rediscovering their form, the Phillies’ bullpen is 11th in NL ERA (4.12). It’s still not where they’d like to be given the high caliber talent of their relievers. New acquisitions Gregory Soto and Craig Kimbrel have All-Star nominations in their past while Seranthony Domínguez and José Alvarado have All-Star appearances in their future.

Obviously, this bullpen is still working with a small sample size of just 59.0 innings pitched in their last 17 games. Thus, one must look under the hood at advanced stats to get a better picture of what the bullpen’s performance really means for the future of the club.

Their 3.41 FIP ranks seventh in MLB, putting them third among all teams in fWAR, trailing only the Baltimore Orioles and Atlanta Braves. Led by Soto and Alvarado, Philadelphia’s bullpen had been dominant in preventing free passes and retiring hitters via the strikeout.

Alvarado is still yet to allow a walk this season; he’s struck out 15 since Apr. 7. Soto, meanwhile, has struck out nine and walked only two since returning to Philadelphia. After allowing five runs in his first three appearances, he surrendered only one in his next nine games.

Examining an even smaller sample size, the Phillies improvement is nigh improbable.

Over their last 21.0 IP, no Major League bullpen has a lower ERA than the Phillies at 0.86. They lead MLB in FIP too by a ridiculous margin, 1.28 to the second-place Washington Nationals’ 2.06.

Their development has been powered by two things, and looking at the past volatility of the Phillies’ relievers, it’s a shock they’ve been able to extend their run of form as long as they have. In the past eight games the Phillies bullpen has not allowed a home run. They’ve also only walked three batters in that span.

The bullpen has excelled not by striking batters out, like they were built to do with their litany of high powered arms, but by control.

Alvarado is the chief exemplar of that. He’s become the best reliever in baseball over the past 10 months and he’s propelled that dominance through the end of 2022 and into 2023.

Just two seasons after having the highest BB% of any reliever in baseball (min. 20.0 IP), Alvarado now sports the lowest walk-rate in MLB, 0%. His transition is almost impossible to quantify. Normally when relievers try to increase their command, it comes at a cost to their stuff, but somehow Alvarado’s K% has only increased, it’s also the best in baseball right now at 55.6%(!).

Very rarely will the best strikeout pitcher in baseball also be the pitcher with the best command, but somehow the Phillies have found that player.

A shining beacon for what the rest of the Phillies bullpen can become, manager Rob Thomson should lean on Alvarado as Terry Francona once leaned on Andrew Miller in 2016 or Joe Torre once leaned on Mariano Rivera. He’s that good.

The Phillies bullpen as a whole will not continue to sport that 0.86 ERA for the rest of the season, but given their recent success, it’s not impossible that they end up MLB’s best relief corps for the last five months of the season.