The Rays Bullpen Has Turned It Around

A few months ago, I took a look at the Rays pitching staff. Despite having the best offense in the league, the team had fallen back to earth after a red-hot start to the season. Surprisingly, their biggest weakness was relief pitching, an area where the team has long had a reputation for excellence. Even with strong offensive showings and a league-leading wRC+, their revolving door of bulk guys and back-of-the-bullpen options simply wasn’t keeping runs off the board. Headed down the stretch, the Rays boast the fourth-best record in baseball and sit just three games back of the AL-leading Orioles in the East. The bullpen has turned it around in a big way. When I last checked in on them in June, their relievers ranked 29th in FIP. Since then, they’ve been in the top five:

One of the biggest reasons for this improvement has been greater stability in the starting rotation. Despite Shane McClanahan going down with a torn UCL after the early-season losses of Drew Rasmussen and Jeffrey Springs, this is the closest thing the Rays have had to a regular rotation all year. After missing two months with an oblique injury, Tyler Glasnow has returned to form, with a sub-three ERA and a 34% strikeout rate. They’ve also made the most of Zach Eflin’s elite command; he currently ranks fourth among AL pitchers in WAR and has almost doubled his previous career high. They moved aggressively at the deadline, trading top slugging prospect Kyle Manzardo for Aaron Civale, who’s improved his K-BB% by nine points since leaving Cleveland. And finally, they’ve converted up/down reliever Zack Littell into an effective starter, because what can’t they do? Since being added to the rotation at the end of July, his 5.8 innings per start ranks in the top quarter of all starters.

The biggest advantage of this somehow excelling rotation has been the removal of the team’s previous crop of long relievers from the roster. The trio of Josh Fleming, Yonny Chirinos, and Cooper Criswell – who had been used in three- or four-inning appearances after openers — have all been optioned or DFAd, significantly boosting the staff, especially in the strikeout department. Greater length and consistency from the starters has allowed the Rays’ single-inning relievers to thrive, with many making significant improvements in the past couple months:

The bullpen’s early-season outings were often characterized by too many walks and not enough strikeouts. While they were often able to strand runners and wriggle out of jams (overperforming their FIP by over half a run), the good performances were largely unsustainable. These weaknesses had already manifested themselves in lost games, as evidenced by Tampa Bay’s below-average reliever WPA. Improved command was clearly an important and necessary goal for the team, and they’ve made substantial progress there.

The most evident change in approach can be seen with a simple glance at the bullpen’s zone rates. As a whole, Rays relievers have landed about 2.5% more of their pitches for strikes, with almost everyone seeing some form of improvement. But they haven’t just been spamming the zone and hoping for the best, they’ve also been executing pitches in better locations to generate swinging strikes. The Rays’ team-wide Location+ ranked 19th in the first half of the season; since then, they’ve been in sole possession of first. This change in process has also led to a change in results. By throwing better strikes, Tampa Bay’s pitchers have gotten into more favorable counts, setting up out-of-zone pitches for strikeouts. Indeed, their seven-point increase in chase rate absolutely dwarfs any other team, as does their boost in K-BB%:

While nearly the entire bullpen has experienced a boost in performance, the Rays’ knack for fixing pitchers is most evident in the rise of Robert Stephenson. Though he’s always had above-average strikeout rates, he’s taken it to another level since moving to Florida, fanning nearly 43% of batters faced. Immediately after being traded from Pittsburgh, he altered the shape of his primary pitch, a cutter/slider hybrid that he uses about two-thirds of the time. He added four ticks of velocity at the expense of movement, bringing it up to 89 mph on average. While the slower breaking ball had a bit of sweep to it, the new pitch (labeled as a distinct cutter by Statcast) has almost no movement outside the effects of gravity, with nearly pure gyro spin. Even with less movement, the cutter pairs better with his upper-90s fastball with tail and carry.

What seems like a relatively minor tweak has transformed Stephenson from an inconsistent pitcher with good stuff into a high-leverage ace. Compared to the old slider, the new pitch has struck out 15.6% more batters, allowed a wOBA nearly 200 points lower, and generates 2.5 more runs above average per 100 pitches. The cutter has turned Stephenson into the league’s premier swing-and-miss pitcher. Since joining the Rays at the beginning of June, his 28.4% swinging strike rate is on pace for the highest ever, and the gap between him and second place Félix Bautista is the same as the gap between Bautista and 44th place Alexis Díaz.

While the staff as a whole has been cruising, some potential playoff roster candidates have emerged at the eleventh hour. Andrew Kittredge was activated from the IL in mid-August. Kittredge, who underwent Tommy John surgery last season, has been an above-average groundball pitcher with experience pitching multiple innings at a time in high leverage. More intriguingly, the Rays also signed Chris Devenski as a free agent after he was released by the Angels in July. After a hot start to the season, Devenski allowed at least one earned run in eight of his final 10 appearances before being released with a 5.08 ERA. Still, the Rays liked what they saw in the underlying pitch data and tendered him a contract.

Once a dominant multi-inning weapon for the Astros, Devenski hasn’t had an above-average season since 2017. Early in his Angels stint, he seemed to have returned to form on the back of his signature changeup, which he has dubbed the “Circle of Death.” As his fastball’s vertical movement declined, he began to rely more on the changeup, scaling it up to 50% usage this season. The pitch plays up due to its outlier release point, as Devenski is the only right-handed pitcher to release the ball on the left-hand side of the mound. During his delivery, it appears as if the rest of his body falls towards first base, getting out of the way of his right arm. The release point, combined with above-average horizontal movement, gives Devenski’s changeup the most extreme arm-side horizontal approach angle of any big league pitch. His PitchingBot grade of 71 ranks third among all changeups, and his 80th percentile swinging strike rate on the pitch backs that up.

Just a few short months ago, it looked like the Rays’ pitching staff would crumble to bits against any formidable playoff offense. Now, their best arms can compete with any team’s. Just two AL teams (the Mariners and Twins) have a trio of starters with more combined WAR than Glasnow, Civale, and Eflin, this despite the former two combining to miss four months with injuries. The retooled back end of the bullpen of Stephenson, Fairbanks, Poche, Adam, and Armstrong can go toe to toe with any other, and the team boasts a host of middle-inning options who could be closers on other squads. It was odd watching a group of arms that didn’t really resemble a Rays staff. But with the right improvements and upgrades, the group looks perfectly Rays-ian once again.