Over the weekend, the Indians added two arms to the bullpen – both with a common denominator: they are among the best at inducing weak contact.
Relievers Matt Belisle and Carlos Torres, who agreed to minor league contracts with the Indians, are among the leaders at Average Exit Velocity Against (AEVA.)
With a minimum of 150 batted ball events, Torres ranked fourth and Belisle 31st, according to Adam Burke. This continues a trend for the organization in which they value pitchers that keep hitters from hitting the ball hard. With a minimum 50 batted ball events last season, Hoby Milner led Major League Baseball in AEVA (Indians took in the Rule 5 draft, but returned), Andrew Miller 2nd, Tyler Olson 10th and Ryan Merritt 18th.
It’s obvious the Indians place value on AEVA. Does it account for anything worthwhile?
It seems like there might be some sort of relationship with production (FIP) and AEVA, and most of this relationship is due to home runs, but this is where it starts to get difficult between what we have and what we want. Home runs are hit very hard and limiting them leads to a lower ERA and FIP.
In a small sample, it appears that pitchers with lower-than-average exit velocities succeed in limiting home runs as compared to their brethren on the other end of the spectrum — and removing home runs from the seasonal exit velocities results in essentially the same exit velocities overall.
What general managers really want to know is if lower exit velocities are a repeatable skill and if the Indians might’ve exploited a market inefficiency. If they are — and if we were able to solidify the link between those velocities and home runs — general managers could identify pitchers we might expect to allow fewer home runs in the future.
Have the Indians proven a correlation?
There is some indication that batted ball velocities are at least a portion of the pitcher’s responsibility and that they stabilize, but more research, more data, and more accurate data is necessary before front office executives can get to the bottom of it.
The Indians have one bullpen spot with several pitchers vying for it. Both Belisle and Torres, will have an opportunity to compete for it.