Is your team a contender in need of bullpen help? I have a reliever for you. He has a 2.47 FIP, 2.94 xERA, 3.28 SIERA, and 85 DRA-. One-third of plate appearances against him result in strikeouts, opponents are managing an average exit velocity of just 86 miles per hour. On top of it all, he throws left-handed and is not strictly a specialist.
Surely this would pique your interest. Even if this pitcher is not elite, he would fit nicely into any contending club’s relief corps. As a rental player, bringing him aboard would not require you to part ways with any significant prospects. Now for the reveal. Who is this reliever?
It’s Ross Detwiler.
Yes, that Ross Detwiler, the 35-year-old career swingman who has a 90 ERA+ across 13 seasons. He posted a 6.60 ERA across 182 innings from 2015-2019. During that stretch, he failed to crack an MLB roster in 2017 and threw just six big-league innings in 2018. He is now pitching for the Miami Marlins, who currently sit at ten games under .500. At nine games out of first place in the National League East, they appear likely to sell off a few pieces at the trade deadline.
Forget the uninspiring track record. Relievers are odd creatures. Every season, there are bullpen arms who have strong seasons out of nowhere, and Detwiler appears to be one of those guys. He has started two bullpen games but has essentially functioned as a full-time reliever this year. In 28 appearances, he has worked 26 2/3 innings. His 3.71 ERA does not jump off the page, but as mentioned above, many of the advanced metrics hold his work in high regard.
Again, Detwiler is not an established high-leverage reliever. Even the bottom-dwelling Marlins have used him primarily in one or two run deficits. However, he has turned himself into a legitimately effective reliever by adjusting his approach on the mound. With a few more tweaks, he could be even better.
Pitch Mix Evolution
For much of his career, Detwiler was a sinkerballer. However, his sinker was never an especially effective pitch. Opponents have managed a wOBA north of .340 against it in eight of Detwiler’s 13 seasons. This season, he is using it a career-low 18% of the time. The four-seamer has taken over as his primary fastball and is inducing whiffs at a 28.6% rate.
While this adjustment is contributing to his newfound success, the driving force behind Detwiler’s resurgence has been the rise of his new cutter/slider. In 2020, Detwiler threw more sliders than he did any other pitch for the first time in his career. While PITCHf/x continues to see it as a slider, Statcast has been labeling it as a cutter this year. Detwiler has shed some of the vertical movement on his main pitch to better differentiate it from his curveball, which he is now utilizing 12.1% of the time. Whether it is a cutter or a slider, the lefty has modified its shape and added nearly two miles per hour of velocity to it. It has been an extremely effective pitch. In addition to a 27.6% whiff rate, it has proven difficult to barrel up, holding hitters to a .171 wOBA, .197 xwOBA, and an average exit velocity of 83.3 miles per hour.
Detwiler’s refined pitch mix has transformed him from an extreme pitch-to-contact guy to a strikeout machine. The veteran has posted a 30.2% strikeout rate this year, which is more than double his career rate of 14.6%. The new arsenal has also eliminated his previously drastic platoon splits. For his career, Detwiler has held same-handed hitters to a .642 OPS, but right-handers have pounded him to the tune of a .296 batting average and .827 OPS. This season, he is completely shutting down right-handers, who have hit just .175 with a .495. The new Detwiler is not just a specialist. He is excelling against opposite-handed hitters.
Room For Further Adjustments
While his current pitch mix is working just fine, it would not be a surprise to see Detwiler go all-in on the cutter if he switches threads. In the first half of the 2018 season, Jesse Chavez posted a solid 3.51 ERA out of the Texas Rangers bullpen. He was using his cutter as his go-to pitch for the first time since 2014. 30.1% of his offerings were cutters, and the pitch held opposing hitters to a .202 wOBA. After the Chicago Cubs traded for him, Chavez took his cutter-heavy approach to another level. He turned to it a whopping 46.6% of the time en route to a 1.15 ERA. His strikeout rate increased to 29.4%. If a contending team brings Detwiler aboard, they might encourage him to get as much mileage out of his best pitch as possible so long as it continues to be effective.
There are some other potential tweaks that might help the southpaw find even more success. While he has basically dumped his sinker against right-handed hitters, he still throws the majority of his fastballs down and inside to them. He also continues to use the sinker as his primary pitch against left-handers. 80% of his total sinkers thrown in 2021 have been to same-sided hitters. Detwiler has always had more horizontal run on his fastball than rising action, but it would not hurt to have the elevated heater as a weapon in his back pocket.
There are a couple of blemishes in Detwiler’s profile. He is walking more hitters than you would like to see, and his 4.2% home run to fly ball ratio is ripe for regression. He lacks experience in pressure situations with a lead. However, he is having a solid season, and several advanced metrics believe that he has performed even better than his bottom-line results would indicate. The veteran has made substantial changes to his arsenal and approach, and it’s working.
Ross Detwiler can help a contending bullpen in the second half of this season. He can provide important innings in the middle of games and bridge the gap to a team’s late-inning arms. With a few more tweaks, he may even be able to fill a higher leverage role. Most importantly, as a veteran rental reliever with an uninspiring track record, his price tag ought to be quite low. With some short-term upside and relatively little risk, teams in need of some bullpen depth should consider checking in with the Marlins on Ross Detwiler. He could prove to be a bargain acquisition.
Photo by Jeff Robinson/Icon Sportswire | Feature Image by Justin Redler (@reldernitsuj on Twitter)