Breakout Relievers Due for Regression In 2019

March 11, 2019

Which relievers who broke out last fantasy baseball season could be due for negative regression in the 2019 MLB season? Connelly Doan looks at relievers who could be overvalued in fantasy drafts.

One of the hardest positions to pinpoint fantasy value for each season is a relief pitcher. You have your handful of dominant closers who are fantasy staples, but the remainder of fantasy value usually comes from surprise players who step into the closer role or are starters with reliever eligibility. With the progressing shift towards closer by committee and deviations away from using a traditional closer in general, it makes finding quality fantasy relievers that much harder.

So when the fantasy world watches relievers break out over the course of the previous season, they rush to snatch them up in the draft based on that performance. While some of these players will repeat what they did, others will regress back towards their production levels from the rest of their careers.

No one wants to overpay for a reliever, so in this article, we are going to look at a few 2018 breakouts which are due for regression in 2019. Note that impending regression does not mean that these players won’t have any fantasy value; it means that they are projected to have less value than the season prior. With that being said, let’s dive in!

Blake Treinen (OAK) ADP - 61

We will start with Blake Treinen because he is the biggest example of the caveat I mentioned regarding regression. Treinen came out of nowhere as one of 2018’s best closers; his 38 saves were a career-high and tied for fourth-most in baseball. He also posted a career-high in strikeout percentage (31.8% vs career 23.8%) and a career-low in ERA (a minuscule 0.78 vs career 2.64) and WHIP (0.83 vs career 1.22). After such a stellar season, it makes sense that he will be targeted highly in 2019 drafts, and he should be. Treinen will be a solid fantasy option, but a look under the hood suggests that a repeat season at that level is unlikely.

Treinen’s career season was made possible in part thanks to good luck. His .230 BABIP was significantly lower than his .304 career mark, which cannot be fully explained solely by his move to Oakland’s pitcher-friendly Coliseum. He also posted a career-low HR/FB rate of 4.4% (vs 9.6% career) while simultaneously posting a career-high fly ball rate (15.6%) and launch angle (6.6 degrees).

These contradictory measures are unsustainable over time, and at age 30, it seems unlikely that Treinen will once again overachieve to such a degree compared to his career numbers. He does have strong job security on a competitive team and pitches in a great pitcher’s park, so fantasy value is still abundant. However, I would be shocked to see him pitch as successfully as he did in 2018.  

Shane Greene (DET) ADP - 267

This reliever broke out in his first year as a full-time closer. Detroit Tigers’ Shane Greene took over as the team’s closer in 2018 and provided 32 saves for fantasy owners with a respectable 23.3% K% and 6.8% BB%. However, those were about the only respectable things he offered.

Greene posted an ugly 5.12 ERA and 1.37 WHIP, which were in line with his career numbers (4.89 and 1.39, respectively). He also posted a ridiculously high 1.71 HR/9 rate. While this number is much higher than his career mark of 1.07, it would not be surprising to see a subpar number again in 2019; Greene’s fly ball percentage has increased in each of his last three seasons.

Overall, Greene profiles as a subpar, fly ball-prone pitcher who happened to get the closer’s role on a weak team. While reports say that Greene is the front-runner to start the 2019 season as Detroit’s closer, he could easily lose the job to another talented bullpen arm such as Joe Jimenez if he pitches like he did last season. At best, Greene could only help fantasy owners in terms of saves, and at worst, he could lose his job and provide them with nothing.

Brad Boxberger (KC) ADP - 371

This pitcher delivered his second fantasy-relevant season in 2018. Brad Boxberger hadn’t been a fantasy name since 2015, but he was able to snag 32 saves for the Diamondbacks with 70 strikeouts over 53 ⅓ innings pitched. He is now on the Royals which is not nearly as competitive of a team, but he will have chances to see save opportunities if he can win the closer’s job. While fantasy players may be interested in him as a middle-to-lower-tier closer, Boxberger’s stats suggest that he may not present much fantasy value in 2019 even if he does get the closer’s job.

First, there are a few apparent blemishes in Boxberger’s 2018 stats line. His ERA (4.39) and walk percentage (13.6%) were fourth-highest and second-highest amongst all relievers with at least 20 saves. He was also tied for the most blown saves with eight. These numbers do not typically equate to an effective reliever, so it is unreasonable to think that Boxberger’s profile will translate to quality fantasy value next season.

Things don’t get better after digging deeper. Boxberger’s average fastball velocity of 91.3 MPH ranked in the 29th-percentile of pitchers, and his average fastball velocity has steadily declined in each season since 2015. Further, his average exit velocity of 89.1 MPH ranked in just the 13th-percentile of pitchers.

The less-than-stellar peripherals coupled with declining velocity does not bode well for Boxberger’s fantasy value, leaving him little to offer for fantasy managers even if he does earn closing duties with his new team.

Craig Stammen (SD) ADP - 538

Our final pitcher turned in one of the best seasons of his career in 2018 at age 34. Veteran Craig Stammen amassed 23 holds over 79 IP, which was tied for 12th-most in baseball, and his K% (27.8%) and WHIP (1.04) were significantly higher and lower than his career averages, respectively (19.5% and 1.26). He also added eight wins to his totals.

The increase in strikeouts and decrease in hits was likely due to a decreased contact rate (71%), his lowest since 2012. In turn, Stammen’s decreased contact rate could be attributed to the vertical movement he got on his main pitches; his sinker and slider had their greatest average vertical movement since 2012 and 2010, respectively. If the peripherals seem to be supported by advanced metrics, why would I think that regression is coming for what appears to be a solid fantasy option in holds leagues?  

My answer to that is two-fold. First, age is not on Stammen’s side. He will be 35 years old for the 2019 campaign, and you never know how players will hold up as they age. Second, 2018 looks to have been a career season for Stammen across the board. The stats that contributed to his pitching success (K%, WHIP, contact rate) were all markedly better than his career numbers, so it seems only natural that they would return towards the norm. Plus, stats like wins and holds are difficult to predict, yet carry a good deal of fantasy value in certain league types. Even if Stammen were able to replicate his stellar stats but only got, say, three wins and 10 holds, his fantasy value would be significantly lower.

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