Pittsburgh Pirates: Unluckiest Pitches of the 2023 Season

Quinn Priester’s Slider - wOBA: .425, xwOBA: .339

Quinn Priester struggled in his first call-up to the big leagues. Although he looked slightly better in his second go around, Priester still struggled overall. But he only just turned 23 in mid-September. But one of his more promising developments was his slider, which while knocked around the park, certainly showed potential as an above average offering.

Opponents had a .295 batting average, .659 slugging percentage, and .425 wOBA against his slider. However, it had some aspects that made it look like it could be a reliable pitch in the future. The first is his 41.4% whiff rate. Of the 454 pitchers who used a slider in at least ten match-ups, Priester had the 76th highest whiff rate. That was higher than standout starting pitchers like Merrill Kelly, Kodai Senga, and Braxton Garrett.

The second reason is the expected numbers looked a lot better. Batters had a .250 xBA, .439 xSLG percentage, and .339 xwOBA when facing Priester’s slider. That’s a lot better than batting nearly .300 with a SLG percentage above .600, and wOBA above .400. Now granted, .339 is still below average. However, it’s a difference of nearly 86 points. That is a Grand Canyon-sized gap.