Luis Avilan’s dominant pitch

Sometimes it’s easy to forget that not every left-handed reliever is a LOOGY (“Lefty One Out Guy,” for the uninitiated). When your favorite team is in a close game and a lefty masher comes up to bat in a big situation, it’s natural to ask why the manager isn’t signaling to the bullpen for his southpaw. Remember, it’s not always that simple.

In 2016, Dodgers left-handed reliever Luis Avilan became the embodiment of this concept. Sure, he was great against lefties, but he absolutely decimated righties.

Holy strikeout-rate-against-right-handers, Batman!

In his five years of big league action, Avilan has only thrown 217 ¹⁄₃ innings — so really everything we talk about here is a small sample size — but his domination of right-handers was a new development even in his short career. In 2015 he posted a 2.61 FIP against lefties but a 4.58 FIP against righties. His 42.9 percent strikeout rate against right handers in 2016 was a huge improvement over his 20.8 rate the previous season. Avilan took a monster step forward last year, and how he went about it is clear: opposing hitters saw more changeups than ever before.

Chart via Brooks Baseball

Typically the changeup’s main use is as a weapon against opposite handed batters, aiming to induce swings low and away. Avilan certainly relies on the pitch heavily against righties, but in 2016 he started throwing it to lefties quite a bit as well.

Data via Brooks Baseball

From 2015 to 2016, Avilan increased his changeup percentage against left-handers from 12 to 37 percent and against right-handers from 45 to 61 percent. Overall it became his most used pitch, barely eclipsing his fastball.

The numbers plainly show why he leaned so heavily on the pitch in 2016. According to Baseball Savant, of pitchers who threw at least 100 changeups last season, Avilan’s offering had the highest swinging strike rate in baseball at 29.7 percent, barely edging out Felipe Rivero’s 29.6 percent. His changeup also had the second-highest swing and miss percentage — a measure of whiffs compared to total swings — of 57.1 percent, falling just short of Rivero’s 57.7 percent.

When looking at a scatter plot of changeup swing and miss rate compared to changeup usage, Avilan represents one of those lone points on the periphery that sticks out like a sore thumb. Only Deolis Guerra threw a higher percentage of changeups and only Rivero had a higher swing and miss rate on the pitch.

Chart via Baseball Savant

So Avilan threw his changeup more than ever and it was more effective than ever. How’d that happen?

The pitch has always had a consistent velocity, but 2016 saw it with its smallest horizontal movement ever. While the pitch showed slightly less fade than an average left-handed changeup, it had far more drop. Avilan’s ability to locate the pitch consistently at the bottom of the zone seemed to mitigate any loss of horizontal movement last season.

Heatmaps via Baseball Savant

The consistency of location coincided with a more consistent release point.

Charts via Baseball Savant

Finding a consistent release point seems like a key to Avilan’s success. Using ‘Release Differential’ and ‘Release to Tunnel Ratio’ from Baseball Prospectus’ new pitch tunneling metrics, we can see that last season he was able to decrease the difference in his release point when throwing a fastball and changeup back-to-back. In theory this created greater deception between the two pitch types, both at release and through the tunnel point.

As is usually the case in baseball — and life, if we’re being honest — success is due to a combination of factors, not just one singular element. With Avilan, he was able to find a more steady release point which then seemed to enable him to locate the pitch more consistently. This in turn allowed him to use his changeup more often and more effectively against hitters of both handedness.

There’s a good chance that the Dodgers open the 2017 season with three lefties in their bullpen, with Avilan presumably joined by Grant Dayton and Adam Liberatore. It won’t be a case of LOOGY overkill. When the Dodgers find themselves in a big spot, with an opposing right-hander up and Avilan on the mound, remember that his changeup is more than up to the task.