Young pitchers often say the changeup is the most difficult pitch to get a feel for, and it seems Romero would agree. After mild effectiveness during his debut season (20.8% K rate, 86 mph exit velocity), Romero’s changeup jumped from 90 to 92 mph last season and he almost completely threw it out of his repertoire.
Having such a live arm, Romero has struggled with command of his fastball. Sitting 97 mph is great, but only if you know where it’s going. His heatmap lights up brightly right down the middle, with a smattering of pitches far off the plate or at the batter’s eye level. Such is why his fastball’s K:BB ratio was 1:7, while opponents hit better than .400 off it.
Nasty and late-breaking, Romero’s slider is gross. It struck hitters out at a 63.0% clip in 2019 while only allowing four hits in 27 PAs.
In 2018, the sinker was Romero’s most frequently thrown pitch, and it produced the expected results. He generated a 65.2% ground-ball rate with the pitch, did not allow a home run and limited batters to a .041 ISO. Romero only had a 5.8% swinging-strike rate on the sinker and walked more than he struck out, which limited its overall value.
Romero’s four-seamer was an effective pitch in 2018. He produced an above-average K rate and limited batters to below-average contact both in and out of the strike zone. As with his other pitches, though, the contact that was made was usually hard. He allowed a high .217 ISO on the pitch as well as above-average fly-ball and HR/FB rates. Romero did throw the pitch in the strike zone 54% of the time; reducing that percentage may help make the pitch become more effective overall.
The slider was Romero’s strikeout pitch in 2018, producing a 33.9% K rate, but this pitch was also hit hard when he missed with it, to the tune of a .164 ISO. Batters chased it slightly more than league average, but when they made contact, they produced high fly-ball and HR/FB rates.
Romero used his changeup the least of his four pitches in 2018, and it produced an overall negative value. Opponents made a ton of hard contact on this pitch—especially when it was in the strike zone, as it allowed an ISO of .192. He needs to get batters to chase this pitch more for it to be effective.