Vanderbilt righties Kumar Rocker and Jack Leiter have been on a very public collision course, battling for the title of “Top Arm” in the 2021 class since the 2020 season ended so abruptly in March. The two opened up a doubleheader back-to-back on Monday, giving scouts and evaluators the opportunity to see them showcase their stuff within hours of each other.
They did not disappoint.
Rocker took the bump first and was sharp for much of his 2021 debut. The tall, burly righty lived 93 to 96 throughout his four innings, touching 98 once according to a scout on-site. He showcased his usual 70-grade slider that was entirely untouchable by Wright State hitters. Rocker mixed in a handful of changeups and a few cutters as well. The cutter lived in the low-90s and was commanded well in on left-handed hitters. The changeup was never landed for a strike.
Rocker’s final line would end up being just four innings, allowing one hit, walking three batters. He did punch out eight and didn’t allow a run. While Rocker’s first four innings were nearly flawless, he started the fifth inning with eight consecutive balls, eventually leading to him being pulled from the game after 67 pitches. When Rocker got in trouble in 2020, it was because of fastball command, usually high and sailing arm-side. Seven of the eight misses in the fifth inning were high and lost arm-side.
The stuff is sublime, there’s no doubting that. Rocker will need to find more consistency with the fastball as he works deeper into contests in 2021. This was his first start of the season. He wasn’t expected to throw a ton of pitches regardless.
Leiter came out throwing octane he didn’t have in his belt in 2020. Leiter touched 98 twice and held 92-97 for his entire start. His command of the fastball was really, really impressive. He was dotting the heater on the corner at the knees arm-side all day and elevated the pitch on the black whenever he wanted. It was a significant swing-and-miss pitch him all day.
Leiter’s feel for his curveball got better as the start progressed. In the first few innings, Leiter threw 10 or 11 of them and only two landed for strikes. The others were generally in the dirt and non-competitive. In the fourth and fifth innings, Leiter began pitching backwards a bit and landed several curveballs for strikes early in counts. He also worked in a few sliders, all of which were commanded well.
His final line was 5 innings, 69 pitches, 0 ER and 1 hit. He didn’t walk any, but he did hit a batter.
As for what this means moving forward, the answer is, well, very little. It’s a long season, and both of these guys should log 60 or 70 more innings under their belt when it’s all said and done. Leiter’s velocity spike is certainly noteworthy. If both Rocker and Leiter are 94-95mph guys this year, the conversation obviously gets a little more interesting. On one hand, Rocker has the better breaking ball and better out pitch. That said, Leiter clearly has superior fastball command and arguably the better operation on the bump. They’re polar opposite physiques, so that will land in the eye of the beholder (Pittsburgh).
It’s not a bad problem to have. Rocker and Leiter both appear to be superior pitching prospects, both of which could anchor a big league staff at the next level in the not-too-distant future.
What to watch for the rest of the way? Rocker’s fastball command and changeup usage. For Leiter, we’d like to see the his curveball or slider commanded well and miss more bats than he did against Wright State.