Seth Lugo was the Mets’ most reliable relief pitcher (again) in 2019

Almost exactly one year ago, I wrote that Seth Lugo was the most reliable reliever for the Mets in 2018. One year later, I find myself writing the exact same thing about this season. Much like last year, the Mets made moves in an attempt to reinforce the bullpen around him—this year it was the signings of Jeurys Familia and Justin Wilson and the acquisition of Edwin Diaz from the Seattle Mariners.

Also like last year, that attempt to reinforce the bullpen ended mostly in failure. Familia was injured and ineffective. Diaz’s season was a mysterious disaster. Justin Wilson was good when healthy, but missed much of the early part of the season due to injury. That left Lugo—bullpen stalwart—mostly alone to hold down the late-inning relief role.

And he did so with incredible aplomb. Despite throwing 20 fewer innings than in either of his previous two seasons, Lugo’s age 29 season was his most productive as a big leaguer. Over 80 innings—exclusively in relief—Lugo posted a 2.70 ERA and an identical FIP. He collected six saves and 21 holds. He pitched to a 150 ERA+ and accrued 2.2 bWAR, 2.2 fWAR, and 2.3 WARP. His 2.2 fWAR mark ranks fourth in baseball among all relievers in 2019. Were he racking up the saves all season long, that would have easily been All-Star caliber.

Lugo’s strength as a reliever, of course, is his ability to deploy a starting pitcher’s arsenal. He throws two fastballs—a four-seamer and a sinker—a slider, a changeup, and of course, his lethal curveball, for which he has become known as the spin rate king. As he transitioned to a bullpen role last season, he was able to not only throw his curveball more often and more effectively, he was able to benefit from an uptick in velocity on all of his pitches working in shorter stints.

This season, Lugo upped the ante. His strikeout rate rose to an impressive 11.7 per nine innings. Concurrently, his walk rate diminished to 1.80 per nine innings. Both are the best marks of his career. Unlike last season, he did not achieve this simply by using his curveball more. In fact, his curveball usage—while still higher than most pitchers—dropped from last season to this season and was paired with an increase in the use of his four-seam fastball. Lugo’s sustained success is coming from his development as a pitcher and his ability to play his pitches off one another with the skill of a master. In September, Devan Fink of Fangraphs took note of this, remarking on how well Lugo tunnels his pitches to keep hitters off balance. Despite how much has been written about Lugo’s curveball, both his four-seamer and his sinker resulted in whiff rates in the 90^th percentile or above this season. These are the marks of an elite high-leverage relief pitcher, something Lugo has indisputably become.

Lugo still considers himself a starting pitcher, however. He has said as much himself. It is likely that his days as a starter for the Mets, even in fill-in or spot start situations, are over, given his incredible success out of a bullpen that desperately needs him. However, the vestiges of his existence as a starting pitcher present a double-edged sword. He has his effective and varied arsenal of pitches, but he also carries with it an inability to pitch multiple days in a row, due in part to a partially torn UCL that is still a ticking time bomb. At times that hurt the Mets in 2019. When Lugo was unavailable, Mickey Callaway had to turn to another reliever, who often did not get the job done the way Lugo would have. The Mets can mitigate this problem with a more competent manager at the helm and more talented arms to deploy, but they cannot erase it entirely.

Nonetheless, the strengths of Lugo as a weapon out of the bullpen far outweigh this one shortcoming. He helped sustain the Mets during their hot streak that propelled them back into Wild Card contention, often pitching the final two innings of close contests. In fact, the argument that the Mets may not have found themselves playing meaningful September baseball without Seth Lugo is not a difficult one to make. As the bullpen crumbled around him, Lugo held steadfast. His poor outings in 2019 can be counted on one hand.

The Mets go into the offseason once again a couple of good relief arms shy of a contender. It remains to be seen whether Brodie Van Wagenen will once again wade into the high-end reliever market (which is relatively shallow this offseason) or if he will pan for gold in the mid-market bunch, trying to land another Justin Wilson or two. Either way, it is indisputable that if the Mets are to contend in 2020, Seth Lugo will have a large role to play in their success.