Beyond the Box Score continues its award series with our two winners for Reliever of the Year, as voted upon by our writing staff.
American League Reliever of the Year, Blake Treinen, Oakland Athletics
Blake Treinen’s 2018 season was the one where he finally put everything together, turning from slightly above-average reliever to literally one of the better players in all of baseball. The pure results were unmatched, as his 0.78 ERA lead all of baseball and was roughly a half run better than second place. The peripherals? Also fantastic. Only Edwin Diaz had a better FIP, only four relievers had a better xFIP. With all of that, Treinen put up 3.6 fWAR, good for 23rd among 273 pitchers with 60 innings this year. Among that same group, he came out first in Win Probability Added.
Treinen saw about nearly every stat move the right way for him this year. His K-rate surged, his BB-rate was at the lowest mark of his career, and after allowing only two home runs on the season, his HR-rate proved to be a career best.
Not only did Treinen put up one of the better seasons by a reliever this year, it’s one of the better performances we’ve seen by a reliever in the 21st century. Only 2016 Zach Britton and 2012 Fernando Rodney posted a lower ERA- than Treinen’s mark of 19 this year. Only 2000 Keith Foulke, 2016 Zach Britton, and 2003 Eric Gagne put up a higher Win Probability Added.
Blake Treinen played a huge part in the major improvement of the A’s this year. He pitched in a lot of those 96 wins they put together, and if they want to replicate that success in any way next year, another good season from Treinen will be a necessity.
National League Reliever of the Year, Josh Hader, Milwaukee Brewers
One of the better breakout seasons in all of baseball this season was that of Josh Hader’s second season in the majors. After being a volatile starting pitching prospect in triple-A, Hader impressed in his half-season debut in 2017. Set for a bigger role in 2018, Hader jumped to another level. His 143 strikeouts led all relievers by a comfortable margin and were the second most post-strike, only trailing 2004 Brad Lidge.
Much like Treinen, Hader played a monumental role in the Brewers run to an NLCS appearance this year. And to top off a dominate regular season campaign, he showed up in October, pitching 7 2⁄3 scoreless frames while striking out 12 and only walking one.
One of the more impressive parts of Hader’s 2018 season was the versatility he allowed Craig Counsell to work with in his bullpen. He was able to go as long as three innings, pitch in setup, close a game out, or even be used in a situational appearance, as lefties hit .088/.186/.169 this year.
At only 24 years of age, Josh Hader figures to be a huge piece to the Brewers future. They’ll need his flexibility to go another season if they want to sustain their hopes at a second straight NL Central title.
Patrick Brennan loves to research pitchers and minor leaguers with data. You can find additional work of his at Royals Review and Royals Farm Report. You can also find him on Twitter @paintingcorner.