Tigers' Alex Wilson is having trouble with runners on base

There were very few bright spots in the Tigers bullpen last season, but Alex Wilson was one of them. Though his addition to Detroit seemed like nothing more than an afterthought in the Yoenis Cespedes trade, Wilson wound up being one of the most reliable Tigers relievers in 2015.

Wilson appeared in the third-highest amount of games among Tigers relievers last seasons and he pitched the most innings out of the pen. With this frequent usage came great numbers as well; Wilson ranked second in ERA, first in WHIP, and second in RE24/IP coming out of the Tigers bullpen.

Despite Wilson’s successes last season, he seemed primed for a smaller role before the 2016 season even began. The Tigers brought in three relievers who all profiled to take over the back end of games, sliding Wilson to a lower-leverage spot. But even with his new projected usage and some injury troubles this spring, there was still belief that he would be an important piece in the bullpen this year.

Two months into the season, it is difficult to tell if Wilson has been better or worse than last year’s campaign. At face value, he seems to have taken a step back, with a sharp rise in ERA and a worse WHIP. Wilson is around even with -0.9 RE24 compared to a team-leading 10.75 last season. His 7.0 percent walk rate is up a bit from the previous two years, and his 38.5 percent hard contact rate is currently a career high.

However, Wilson has also brought down his FIP and xFIP to start off 2016, and he has kept opponents around the same batting average. He has boosted his strikeout rate from 13.9 percent to 19.7 percent, and his HR/9 rate is slightly down. So while some of his numbers show Wilson taking a step back, others make it seem like he is progressing in the right direction.

Runners aboard

Clearly there is a disconnect between the number of base runners that Wilson has allowed and the number of runs that have crossed the plate. While his WHIP is slightly up and the contact against him has been solid, his ERA is not telling the whole story. Instead, the answer lies in what happens when runners get on base.

In 2015, Wilson recorded a 82.1 percent LOB%, a figure that fell among the top quarter of all qualified relievers. This season, that value has plummeted to 61.2 percent. Relatedly, after stranding 60 percent of inherited runners over the course of last season, Wilson has seen that number fall to 45 percent in 2016.

Suddenly it becomes clear why Wilson’s ERA has ballooned. Though he has not allowed runners to reach base significantly more frequently that he did last season, Wilson has become a completely different pitcher when there are runners on. Although his strikeout rate is actually better in 2016, his batting average against and walk rate both shoot up. With the bases empty, Wilson allows line drives just 10 percent of the time, with ground ball and fly ball rates both over 40 percent.

A fixable problem

Wilson has a very interesting profile with men on base, but perhaps he is suffering most from plain bad luck. His .47155 BABIP in these situations is extremely elevated, and his 2.62 FIP is lower than his 3.37 FIP with the bases empty. Perhaps his 65 percent strike rate implies that he is throwing some hittable pitches, but his soft contact rate is over 27 percent when there are runners on, compared to just 6.7 percent with empty bases.

Undoubtedly, Wilson must find a way to improve when runners are on base or he will quickly become more of a liability than an asset. Although he is able to cause soft contact with traffic on the base paths, as long as hitters can square him up for a healthy amount of line drives, he will continue to find problems in these situations. However, there is some reason to believe that the numbers will simply correct themselves over time, and Wilson has proven that he can pitch effectively in other situations. Putting it all together is the next step, and one he must discover soon.