Devin Williams has not been the same in 2021

Devin Williams worked a scoreless inning on Monday night’s series opener against the Chicago Cubs, but that inning came with its fair share of drama. The setup man recorded the first two outs of the inning quickly, but a hit followed by back-to-back walks loaded the bases. After a long battle with Rafael Ortega, Williams notched a groundout to first base on a 3-2 offering to end the inning. He threw 34 pitches, and the high-stress outing left him unavailable for the second game of the series the following night.

While this outing was more extreme than usual, it was an epitome of how the reigning National League Rookie of the Year and Reliever of the Year has weaved his way through his sophomore season. He is not allowing many runs, but he is working through traffic frequently and throwing plenty of pressure pitches. Williams is the latest to assume the role of providing “Twenty Pitches of Terror” in the late innings.

Let’s focus on the positives first. Williams’ ERA and each of his estimators are below 4.00. He has a 3.26 ERA, 3.67 xERA, 3.71 FIP, 3.35 SIERA, and 3.08 DRA in 30 ¹⁄₃ innings of work this season. Those are all solid marks (and his DRA remains closer to elite territory), and none of them are especially surprising. Just about everyone knew that he would not be able to repeat his sub-1.00 ERA from last year.

Williams’ signature changeup has experienced the expected slight regression, but it remains one of the best pitches in the game. The Airbender has continued to limit opponents to a .167 batting average and .223 wOBA while inducing whiffs at an absurd 45.4% rate. Because of this, Williams still allows very few hits (6.8 per nine) and continues to post elite strikeout totals, punching out hitters at a 36.8% rate. This has enabled him to maintain an acceptable ERA and prevent estimators from souring on him.

The Airbender remains awesome, but once we begin to look past it, a couple of troubling trends emerge. The first is one of the worst walk rates in the league. Williams is issuing a base on balls to 15% of total batters faced, which ranks in the fifth percentile. To be fair, he never had the best control; his walk rate was a below-average 9% both last season and in his 2019 cup of coffee with the Brewers. His career walk rate in the minor leagues was 10.8%. This season, however, the free passes are creeping into dangerous territory. Williams has issued at least one walk in 16 of his 33 appearances (48.5%). This has produced an unappealing 1.42 WHIP that places him in the same territory as mop-up relievers and other low-leverage arms.

In addition to his inconsistent control, Williams has lost velocity on his fastball. After averaging 96.5 mph on the pitch in 2019 and 2020, his velocity is down to 95.1 mph this year. Last season, 140 of his 188 four-seam fastballs (74.5%) registered at 96 or above. This season, just 50 out of 211 (23.7%) have reached that threshold. Williams used to throw in the upper-90s with regularity, but he now sits more in the 94-95 range with his previous average now being his high-end velocity.

Baseball Savant

Having a blazing fastball in his back pocket helped make Williams’ changeup even more effective in 2020. It stood to reason that he would need to use the fastball more often over time as hitters grew accustomed to the changeup. Instead, inconsistent velocity and command have made it a non-factor this season. Hitters are torching the 26-year-old’s fastball, batting .347 with an eye-popping .534 wOBA and 95.8 mph average exit velocity against it. Because of its ineffectiveness, Williams is throwing it even less while being forced to lean on his changeup even more. 60.4% of his total pitches are now changeups compared to just 36.3% fastballs.

Baseball Savant

Even if we were to chalk up the location problems to Williams never being a control pitcher to begin with, the velocity drop and ineffectiveness of his fastball are still concerning. One potential explanation is that the shoulder injury he sustained last fall was more severe than the club let on publicly. After initially describing the ailment as “shoulder soreness,” Williams later clarified in March that it was a strained rotator cuff. The Brewers were extremely cautious with him and delayed his spring training debut, but they insisted that their star reliever was healthy. Diminished control and velocity are common side effects that follow a pitcher after recovering from a serious shoulder ailment, and it can take additional time to recover them even after the player is technically healthy again. While the Brewers have not commented on this (and perhaps never will), it is a convenient explanation for Williams not looking quite like himself all year.

His ERA and estimators still look fine, but there is reason to be skeptical of the manner in which Devin Williams has been putting up scoreless innings this year. He is regularly working in and out of self-induced jams with essentially one effective pitch. Not only does that seem unsustainable on its own, but high pitch counts and frequent high-stress pitches could lead to fatigue down the stretch. As long as he continues to protect most leads, he is not at any risk of losing his setup role, nor should he be. However, it’s difficult to shake the feeling that this version of Williams may not be successful for much longer. Time will tell if that is the case or not.

Statistics courtesy of Baseball-Reference, FanGraphs, Baseball Savant, and Baseball Prospectus