Averaging 82.5 mph at just 1886, Hernandez’s changeup drops 8.4 inches on average, but still saw a considerably amount of placement middle-outside rather than lower in or below the zone. Its swinging strikes disappeared in 2019, going from 14.4% to 6.1%, thanks to a 20% jump in his contact rate on the pitch. That contact may have been poor, though, as its .125 BABIP might suggest, or he might just have been lucky not to be punished on the pitch.
Hernandez’s fastball averaged just 90.9 mph in 2019 with 2247 rpm, but still returned a 22.3% K rate. It was placed high and above the zone, and its whiffs reflect that. But batters hit 12 home runs on the pitch on just 777 thrown, which led to a 155 WRC+.
Hernandez’s slider velocity dipped to 79.4 mph, but its spin rate jumped more than 200 rpm to 2245. The resulted in four more inches of total break and a seven point jump in SwStr to 17.7%. A jump in zone rate (49.8%) alongside a huge drop in Z-contact (70.1%) helped him to a 31.6% K rate on the pitch, and a .175 BABIP combined with those strikeouts to earn it a 47 WRC+ and 6.9 pVAL.
For a pitch receiving a 60 grade, it certainly didn’t show a whole lot during Hernandez’s rookie campaign. The velocity was incredibly underwhelming for someone who pitched most of the season out of the bullpen, and it lacked the control or spin to overcome this. Prospect evaluations give some hope that the pitch could improve, but 2018 was a rough major league unveiling of it.
The story of Hernandez’s slider is largely the same narrative dogging his fastball: poor velocity and not enough spin to make the pitch effective. It was no better at drawing strikeouts than the fastball, though it sported a far less unsightly walk rate. In contrast to his fastball, which was hit well by righties but poorly by lefties, left-handed hitters batted .346 against the slider in 2018, though a .193 xBA indicates bad luck played a part in the poor results the pitch drew.
The changeup here is interesting, as the lack of strikeouts, -1.6 pVal and below-average spin rate would seem to speak volumes about how poor the pitch is. However, xStats indicate that Hernandez got far more unlucky with the pitch than he should have. Though the peripherals certainly seem to speak to the contrary, the large disparity between the expected and actual results for Hernandez in 2018 for multiple pitches is worth keeping an eye on in 2019.