Shane Greene made the transition from the starting rotation to the bullpen last season and, while his ERA didn’t show much improvement, his peripheral pitching numbers were quite good. In 47 innings of relief work his stikeout rate rose above 9.1 per nine innings, his walk rate dropped below 2.5, and he allowed the lowest home run rate of his career.
Those secondary numbers combine to give Greene a 2.94 FIP in relief. His ERA out of the bullpen was 5.55. Those number don’t jive very well. The two biggest issues for Greene were a somewhat high batting average allowed on balls in play (BABIP) and a low strand rate for runners on the base paths.
One should easily expect the BABIP to come back down. According to the Statcast data presented on MLB Savant, Greene did not typically allow hard contact. He did a particularly good job against right-handed batters but struggled against lefties (especially when leaving the ball up in the zone).
The low strand rate is harder to analyze — it plagued him in 2015 as well. He seemed to be pitching out of the stretch full-time as a reliever, so he probably wasn’t affected by transitioning from the windup-style delivery (as one might expect from a former starter). Perhaps he felt the need to rush his mechanics with men on base (I’m no expert on those sorts of things) or perhaps it was plain bad luck.
To make matters more interesting, Greene did not seem to struggle when entering a game with runners on the base paths. According to Baseball Reference, Greene inherited 20 base runners in 2016, but not a single one of them came around to score.
It’s hard to say exactly what Greene needs to do to get his ERA to bounce back in 2017 — perhaps nothing — but the Tigers need reliable arms to count on in the sixth and seventh innings. It’s not clear that he has a guaranteed spot on the opening day roster, but he could (and probably needs to) be a guy that could help stabilize the bullpen in 2017.