Leiter vs. Rocker: Who should go No. 1?

Kumar Rocker entered 2021 as the consensus top Draft prospect and has excelled over his first seven starts. He won all seven with a tidy 0.84 ERA, posting a .137 opponents' average and a 61/12 K/BB ratio in 43 innings.

Fellow Vanderbilt right-hander Jack Leiter has been even better. He no-hit South Carolina for nine innings in his first career Southeastern Conference start and Missouri for seven innings before departing in his second. He also has seven wins in as many starts, and his numbers verge on the ridiculous: 0.43 ERA, .074 opponents' average, 71/16 K/BB ratio in 42 innings.

"It's like watching Mickey Mantle and Roger Maris from 1961," an area scout who covers Vanderbilt said. "It's two guys who are clearly elite in their field."

The Commodores aces could become the first teammates to ever go 1-2 in the same Draft. The last time college baseball saw anything like this was in 2011, when UCLA had No. 1 overall pick Gerrit Cole and Golden Spikes Award winner Trevor Bauer. Cole and Bauer went 1-3 that year, as did Arizona State sluggers Bob Horner and Hubie Brooks in 1978.

While Leiter and Rocker clearly are outstanding prospects, who's better? We posed that question to a wide swath of general managers, executives, scouting directors and area scouts.

The result was 25-3 in favor of Leiter, with one executive declaring it a dead heat. That landslide overstates the difference between Leiter and Rocker, with most respondents expressing that they consider the two aces to be extremely close in talent.

"It's hard to separate the two," a National League scouting director said. "Rocker is bigger, more physical and has more track record. Leiter just feels like he'll outperform him. I'm more confident with him reaching his ceiling than Rocker. Leiter has more feel and ability to use his weapons."

At the outset of the season, Rocker's perceived advantages were more physicality (6-foot-4, 245 pounds vs. 6-foot-1, 205 pounds), a bigger fastball (sitting at 93-96 mph and peaking at 99) and a more overpowering breaking ball (a mid-80s slider at its best). Leiter got credit for a deeper repertoire (90-95 mph fastball that touches 97, quality curveball and slider, solid if seldom-used changeup), better delivery and superior feel for pitching. Rocker had a higher ceiling while Leiter offered a higher floor.

The son of two-time All-Star and World Series champion Al Leiter has closed the gap in pure stuff this spring -- his plays better. While he can't reach Rocker's maximum fastball velocity, he's now sitting at 92-94 mph and Rocker has operated a tick below that in his last two starts. Leiter generates significantly more swings-and-misses with his heater in the strike zone thanks to its riding life and outstanding metrics, such as induced vertical break, and an American League assistant scouting director called it one of the best fastballs he's come across in any Draft.

"Leiter¡¯s ability to dominate with his fastball is truly elite, especially in the strike zone," a second AL assistant scouting director said. "Rocker dominates with his secondary stuff, especially out of the strike zone."

When it's on, Rocker's slider is a legitimate wipeout offering that he famously used to record each of his 19 strikeouts in a no-hitter against Duke in the 2019 NCAA super regionals. The son of former NFL defensive lineman Tracy Rocker, he also utilizes an upper-80s cutter that can be better than his slider on a given night.

"Kumar's ability to land and draw whiffs with his two plus-plus breaking balls are a separator, and the fastball is playing better than it did in high school," said an AL scouting director who prefers Rocker despite witnessing Leiter's no-hitter against South Carolina in person. "His fastball command isn't at Jack's level, but it's enough, and he's learned to hunt at the top of the zone late for K's. Both are potential frontline arms, but there's more horsepower to the Rocker repertoire and the body is built for the long haul."

That said, some scouts note that Rocker uses his slider and cutter more as chase offerings and wonder how they'll work against big leaguers with more command of the strike zone. While Leiter's 78-82 mph curveball and 81-85 mph slider aren't as powerful as Rocker's breaking pitches, they can be just as effective.

"As special as Rocker's fastball is, Leiter's is even more special," a second AL scouting director said. "Their breaking balls are similar in quality, but I prefer Leiter's ability to command, shape and tunnel his mix and I think his pitches play better in the strike zone. Leiter can cruise along and then also throttle his three main pitches up when he needs extra velo or depth on the breaking balls."

Neither pitcher uses his changeup much at Vanderbilt, though Leiter flashes a solid one with fade while Rocker's is more average and gets a bit firm at times. They have exhibited similar control, with Leiter battling the strike zone a bit earlier in the season but improving his location once SEC play began with better athleticism and ease of operation. They both earn praise for their intense competitive natures, which prompted Commodores coach Tim Corbin to liken Rocker to Hall of Famer Bob Gibson.

"I prefer Leiter by a pretty good margin," a third AL scouting director said. "He just does what he wants. He can get deep in counts at times so pure command can get him occasionally. But once he locks in, it's four plus pitches, life to the fastball and wipeout stuff. Younger hitters have zero chance."

The biggest question with Leiter is how he'll hold up deep into a season, which he hasn't had a chance to answer yet. While he has gotten stronger in college, he still lacks a big frame and worked just 58 2/3 innings as a New Jersey high school senior in 2019 and 15 2/3 as a Vanderbilt freshman before the coronavirus pandemic ended the 2020 season. Rocker was better than ever at the end of his 87 1/3-inning freshman season in 2019, no-hitting Duke before winning Most Outstanding Player honors at the College World Series.

Rocker was the favorite to go No. 1 overall in February, with Leiter now supplanting him and prep shortstops Jordan Lawlar (Jesuit College Prep, Dallas) and Marcelo Mayer (Eastlake High, Chula Vista, Calif.) also positioning themselves as candidates. Plenty could change before the Pirates have to make a decision on July 11. Leiter and Rocker already are the most hyped teammates in college baseball history, and they may be the most dominant by the time they're done.