Zack Wheeler’s strikeouts rising with better pitch usage

Two nasty breaking balls — including one that he is using more than he ever has — are part of Phillies right-handed starting pitcher Zack Wheeler‘s success.

Slider

Wheeler is throwing his slider about one-quarter (25.6) percent of the time this year, a big change from his approach in the pandemic-shortened 2020 season — when he threw it only 15.9 percent of the time. It’s also a significant increase from his previous career-high 20.3 percent use of the pitch from 2017.

The slider has become a pitch that Wheeler trusts and can consistently fool hitters with, specifically those who bat left-handed. Wheeler has thrown 285 sliders this season and nearly 200 (194) of them have been to lefties.

Overall, opponents have a .159 batting average (10-for-63) with 27 strikeouts against Wheeler’s slider. The pitch also has a 32.9 percent whiff rate and a 31.8 percent putaway rate, which ranks 10th in the majors on sliders.

In addition to how often he throws it, velocity and spin are also important when it comes to the right-handed pitcher’s slider. At 91.2 miles per hour, Wheeler has the second-highest average slider velocity in Major League Baseball — behind only his former New York Mets teammate and perennial Cy Young Award candidate Jacob deGrom (91.6 miles per hour).

The active spin percentage is up on four of Wheeler’s five pitches. Also, his jump from 27 percent active spin on his slider in 2020 to 39 percent in 2021 is by far the biggest spin increase in his arsenal.