Over Guilbeau’s 12.1 innings in the majors in 2019, he turned to his fastball 63.54% of the time, using it to hit the highest ground-ball rate of his professional career at 69.2%, a 9.4% jump from his previous career high. This likely helped him on the way to a .211 BABIP, but with a FIP north of 5, don’t expect his 3.65 ERA to stay where it is in 2020.
Out of the 84 pitchers who throw their changeup at least 25% of the time, only five throw it harder than Guilbeau, who averages 87.66 mph. With less than 7 mph between the average speed of this pitch and his fastball, it’s not surprising to see it generate -1.7 pitch value in his first season in the majors. It was by far his worst pitch.
Guilbeau only threw 13 sliders in 2019, slightly more than one per inning pitched. He’s been an extreme ground ball pitcher throughout his career, so he could start turning to this pitch more often to help supplement his fastball in 2020.