Pittsburgh Pirates: Chase De Jong Needs to Ride His Slider

Reliever Chase De Jong has some worrying underlying numbers, but he could mitigate some of the worries by taking advantage of his slider.

The Pittsburgh Pirates picked up Chase De Jong on a minor league deal last year. The deal was met with little fanfare, as the right-hander struggled in the few appearances he made in 2021 and was nothing more than roster depth in previous seasons. However, De Jong delivered the Pirates with a pretty solid season, even if he wasn’t used in a high-leverage role.

In 71.2 innings, De Jong had a 2.64 ERA and 1.14 WHIP. But De Jong struggled in almost every other facet, only having a 20.1% strikeout rate, 10.1% walk rate, and 1.26 HR/9. The only other positive was his exit velocity was only 88.4 MPH, which was in the 52nd percentile.

De Jong had a 4.96 xFIP and 4.38 SIERA, and he greatly benefitted from a .222 batting average on balls in play (compared to his ‘17-’21 average of .304). Given that there was no major change in De Jong’s batted ball rates, his BABIP is questionable at best.

That means there are a ton of questions surrounding De Jong going into 2023. There’s almost no evidence suggesting that De Jong turned a corner and is all of a sudden a new pitcher that can sustain his 2022 success. But even if De Jong can’t repeat a sub-3.00 ERA season, there could be a way for him to at least pad the fall back to Earth so that he is still somewhat effective as a low-leverage/long-relief arm.

That way could be by taking advantage of his slider. His slider held opponents to just a .170 average, a .307 slugging percentage, and a .241 wOBA. He also had a whiff rate of 41.4% and had an average run value-per-100 of -2.2. In total, only 28 pitchers had an RV/100 of -2 or better, and De Jong ranked 22nd. That’s just below some very notable names like Yu Darvish (-2.4) and Ryan Presley (-2.5) and just above some other guys like Bryan Abreu (-1.8) and Alexis Diaz (-1.9).

De Jong used his slider 29.2% of the time last year, making it the second most used offering in his arsenal. The only pitch he used more often was his four-seamer at 46.6%. He also used a curveball 22.9% of the time, which held batters to a .264 wOBA. But De Jong’s fastball gave him some trouble. Opponents may have only managed a .209 average against it but slugged .491 with a .361 wOBA. Sure, he may not have given up a ton of hits with it, but when he did, they were big hits.

If De Jong increases the use of his slider (and maybe his curveball), he could mitigate some of the regression that seems to be on the horizon for him. He could do this by reducing the amount he uses his fastball. His fastball gave him some trouble last year, and thus a reduction in it’s usage could help him out in 2023.