Michael Fulmer Slides Into a Cubs Bullpen Looking for High-Leverage Help

The offseason is beginning to wrap up, but there are still plenty of names still available to help boost the fringes of teams’ rosters, especially in depth relievers. Last week, Michael Fulmer became the latest of these signings, inking a one-year deal with the Cubs.

The bulk of Fulmer’s big league career has been spent in Detroit, where he won the AL Rookie of the Year award in 2016. With a 3.06 ERA and 3.76 FIP in 159 innings, he looked to be the future ace of a Tigers rotation that had lost Rick Porcello and Max Scherzer a couple years earlier and would lose Justin Verlander the next season. But after two more seasons where he performed around league average and a 2019 campaign completely lost to Tommy John surgery, Fulmer went through a catastrophic 2020, with an ERA near nine and less than three innings per start. It seemed like his time as a productive big leaguer was over, and it was — as a starter. But he’s performed quite well over the past two years in the bullpen, posting career bests in ERA and strikeouts.

While Fulmer had above-average seasons as a starter, he had neither big-time swing-and-miss stuff nor pinpoint command, succeeding despite pedestrian numbers in the strikeout and walk departments. Instead, his best years were characterized by a solid ability to suppress hard contact and home runs, possibly aided by his cavernous home ballpark. He throws two fastball variants but has shown a slight preference for the sinker, which has allowed him to run a groundball rate that’s consistently a few points above the league average.

While Fulmer was always a fastball-first pitcher as a starter, he has made drastic changes to his pitch mix since being converted to a reliever that have contributed to his success.

In his four seasons as a starter, Fulmer’s slider usage topped out at about a quarter of total pitches. That changed in 2021, when he threw fastballs and sliders with roughly equal proportion. But last season, he largely shelved everything else in favor of throwing even more sliders. He was one of 35 relievers (plus one starter) to throw sliders at least half the time in 2022, with a 63.4% usage rate that ranked fifth in baseball. It’s worked out for him, too: the slider has generated a +13.9 pitch value over the past two years; each of his other offerings have registered a negative value during that time.

The rationale behind scaling up his slider usage was clear: the pitch generated a whiff rate above 30% in each season (well above average), and his fastball and changeup had far less bat-missing ability. Without the need to pitch deep into games, Fulmer no longer needed to worry about getting a feel for his heaters; instead, he could simply throw his best pitch most often. Additionally, without the need to face the batting order multiple times, he no longer required multiple different gameplans to beat each opposing hitter, with fewer consequences if a batter saw the same pitch five times in a row.

The Cubs have shown a preference for sweepier breaking ball shapes in their younger pitchers like Keegan Thompson, Justin Steele, and Ethan Roberts, but Fulmer’s slider doesn’t have high marks in horizontal movement. Instead, the name of the game for him is velocity; he was one of only a handful of pitchers who averaged at least 90 mph on their slider. It sat in the high-80s when he was a starter, but he’s thrown it far harder as a reliever despite losing velocity on his fastballs. Its shape almost resembles that of a cutter, although his breaking ball has a bit more vertical drop than most true cutters. Pitch data models don’t see anything special in its movement profile, but it gets by as a hard offering that moves in an opposite direction to his fastball despite a tiny velocity difference. While many of the other pitchers who throw 90 mph sliders can reach back for triple-digit heaters, Fulmer’s fastball sits at 94.2 mph, right around the league average for relief arms.

While Fulmer has phased out the rest of his arsenal, his other pitches still get the job done decently well. His sinker has a career groundball rate of 51%, although it has a measly 4.6% swinging-strike rate, but keeping the ball on the ground is never a bad thing. His four-seamer doesn’t have great carry but it does kill horizontal run well, often leading batters to swing under it and pop the ball up. Indeed, since being moved to a relief role, about a sixth of Fulmer’s fly balls allowed have been of the infield variety, significantly limiting the damage done when hitters put balls into play. According to Statcast, he avoided barrels at a 91st-percentile clip last year and a 68th-percentile rate in 2021, both due to his high groundball rate and the fact that his fly balls were often hit too high to leave the yard.

Fulmer doesn’t really have any standout skill, be it premium velocity, elite control, or a Zack Britton-level groundball rate. But he does everything just well enough — getting his fair share of whiffs with his slider, throwing just enough strikes to not have a dreadful walk rate with such a predictable arsenal, and being slightly above average at most quality of contact stats.

After trading away the core of their 2016 World Series team a couple seasons ago, the Cubs are putting together the pieces of their next competitive squad. And while they have solid production all over the diamond, they’re lacking in prominent names on the pitching side, something their 78-win ZiPS projection reflects. But with a 17.8% chance to make the playoffs in a relatively weak NL Central, they have a non-insignificant chance to start that new competitive window now, especially if new acquisitions like Dansby Swanson and Jameson Taillon have big seasons.

The Cubs’ current bullpen is filled with many solid arms but lacks a high-leverage relief ace. In fact, their best reliever by ZiPS, Jeremiah Estrada, ranks 90th in projected relief ERA. But they do have a few names with some high-leverage experience, including Fulmer, Brad Boxberger, and Rowan Wick. Chicago’s success in finding a dependable closer is dependent on having at least one reliver hit their 90th percentile projection for the season, and Fulmer adds another possible name for a big breakout.