Six MLB relief pitchers with a lot to prove in 2019

Ken Giles, Toronto Blue Jays

Ken Giles‘ tenure with the Houston Astros was up-and-down, to say the least. Although he posted a 4.11 ERA in 2016 with the club, he was still worth 1.5 fWAR thanks to a 35.7% strikeout rate and 2.48 SIERA. His 2017 regular season was more of the same — he accumulated a 33.6% strikeout rate and 2.81 SIERA while lowering his ERA down to 2.30.

The 2017 postseason was the beginning of the end, though. He struggled to an 11.74 ERA and 12.5% walk rate in just 7.2 innings, basically forcing manager AJ Hinch to keep him in the bullpen. It was more of the same this past year, as he struggled to a 4.99 ERA in 30.2 innings and was even sent to Triple-A before getting traded to the Toronto Blue Jays.

Giles wasn’t necessarily a whole lot better north of the border — he was worth just 0.1 fWAR in 19.2 innings thanks to a 4.12 ERA and 1.83 homers allowed per nine innings. There were a couple of encouraging things to glean from his year, though, with one being a significant drop in walk rate. After that number settled in at 8.4% or higher between 2015-17, it dropped to 3.3% in 2018.

The other is a change in his batted-ball profile. Take a look at how his line-drive rate (LD%), ground-ball rate (GB%), fly-ball rate (FB%), soft-hit rate (Soft%), and hard-hit rate (Hard%) shifted from one team to the next:

A handful of these numbers likely aren’t sustainable over a longer period of time, but some are more closely aligned to his 2017 regular-season performance. He doesn’t have much competition on the Jays’ roster for the closer job, but 2019 will be crucial prior to his final year of arbitration, as well as his eventual free agency soon after.