Arms Factory

Vanderbilt has become to hurlers what Penn State is to linebackers. The latest talents turned out by Pitcher U., Kumar Rocker and Jack Leiter, could be two of the best.

Vanderbilt pitchers Kumar Rocker and Jack Leiter stand across from each other in the outfield before each contest, stretching their pregame warmup from short-range throws to long tosses across the turf. 

Rocker and Leiter are the latest in a long line of elite pitchers the school has recently produced—All-Stars Walker Buehler, Sonny Gray, Mike Minor and David Price are among the eight former Commodores pitching in the majors—yet neither fits the prototype of a staff ace. Rocker looks best-suited to chase quarterbacks across the SEC. Leiter could reasonably be mistaken for an intramural shortstop on his way to class. But on the mound, this odd couple is anything but out of place.

Opponents facing Vanderbilt in weekend series in 2021 endured a pair of vastly different, yet similarly frustrating experiences. Rocker, a junior righthander, would take the ball in the first game. Standing 6' 5" and weighing 245 pounds, he’d sport a cutoff compression shirt during warmups while hurling fastballs that approached triple digits. After working himself into a lather as first pitch neared, the real Rocker show would begin.

Rocker pairs his electric fastball with a violent slider and a cutter. He challenges hitters on every pitch, grunting and celebrating his way through each start. Rocker doesn’t as much throw to the plate so much as he attacks it. “I’m going to make you look stupid, or you’re going to make me look stupid,” he says. “Simple as that.”

For the most part, it has been the former over the course of his Vanderbilt career. Rocker struck out 114 batters in 99 2/3 innings as a freshman two years ago, including 19 in a no-hitter in the 2019 Super Regional against Duke. He finished that season by striking out 11 in 6 1/3 innings against Michigan in the College World Series finals, earning Most Outstanding Player honors as the Commodores won their second national title. This year, he fanned 135 hitters in 99 1/3 innings and carries an 11–3 record into the NCAA tournament, which gets underway Friday.

Illustration by Martin Laksman

It’s natural to exhale after an evening against Rocker. But there was no reprieve for Vandy’s opponents upon arriving at the ballpark the next day.

Leiter doesn’t boast the same intimidation factor as his counterpart. The sophomore stands just over 6 feet, spending his warmup draped in a team jacket. Leiter doesn’t yell on the mound. Any grunt is only faintly audible. His glove covers his face for much of the time he is on the mound, and you need to comb through each outing like the Zapruder film to find a smile. While Rocker revs his engine, Leiter provides a steady hum.

Though perhaps Leiter is more like his fellow ace than he’s given credit for. “Don’t be fooled to think that is a passive dude,” says Al Leiter, Jack’s father and a former MLB All-Star pitcher himself. “Internally, he wants to rip your face off.”

The younger Leiter’s stoic demeanor served him well in his first full season with the Commodores. Since the 2020 campaign ended before SEC games began, he didn’t make his conference debut until March 20 of this year, when he struck out 16 in a no-hitter against South Carolina. (The previous night, Rocker struck out 14 in eight innings in a 3–2 win.) Leiter then tossed seven additional no-hit innings before being pulled against Missouri six days later. (He had thrown 101 pitches; the Tigers broke up the no-no in the ninth.) Leiter allowed just three earned runs in his first 49 innings in 2021, a stretch that included 84 strikeouts and an .082 opponent average, and he'll go into tournament play with an 8–3 record and a 2.28 ERA.

Their success hasn’t just bolstered Vanderbilt’s reputation as Pitcher U. It’s also solidified their places atop the draft board. As a 20-year-old sophomore, Leiter will be eligible for this summer’s draft, where he and Rocker have a chance to make history as the first teammates to go 1–2. So the pair are likely to leave Vandy under similar circumstances. Their journeys there were very different.

Leiter’s path to pitching stardom began when he was still in diapers in the early years of the 21st century. Al, then with the Mets, littered the family’s Queens apartment with dozens of plastic balls, similar to the ones you’d find in the ball pit at Chuck E. Cheese. Jack quickly began chucking them at every turn, with Al standing behind him to raise his elbow to the appropriate height. Jack would join his dad at Shea Stadium and ballparks across the country as he grew up, glove and ball in hand at every turn.

Leiter tossed a no-no in his first SEC start :: David E. Klutho/Sports Illustrated

The father-to-son pipeline is a common theme in MLB history. There were 17 players on 2021 Opening Day rosters who are the sons of former major leaguers. So Jack’s crashing the majors wouldn’t exactly be an anomaly, though his path to the pros wasn’t the same as his dad’s.

Al joined the Yankees organization out of high school in 1984, and, despite a strong arm, he struggled initially at the professional level. Al says he was a thrower rather than a pitcher, citing the age-old saying for young arms who haven’t found their footing. But after a pair of shoulder operations in the late 1980s, his career changed forever. He has Harvey Dorfman to thank.

Dorfman, the author of The Mental Game of Baseball, became one of the nation’s first sport psychologists in the 1980s, earning a World Series ring with the A’s in 1989. Leiter began working with him in the early 1990s, and, under Dorfman’s tutelage, he found a guiding light. Leiter also retooled his delivery with the help of former pitching coach Gil Patterson following his surgeries. By the time he pitched his first full big league season, with Toronto in 1993, he was displaying a Zen that was unrecognizable compared with his previous attitude on the mound. Leiter went on to win 162 games and three World Series rings, throwing a no-hitter of his own in 1996, when he had evolved from a power pitcher to a craftsman. “Through Harvey, I figured out what my job was. I created this mantra,” Leiter says. “I really like to think there weren’t too many guys too mentally prepared with what the job was, and that was to not allow exterior distractions to come into the task at hand. I learned that from Harvey.”

Dorfman’s teachings have filtered down to Jack, both intentionally or “by osmosis,” as Al puts it. Ask Jack about the best parts of his arsenal, and he quickly pivots to a discussion of his thought process. “My mental focus is probably my best skill,” Jack says. “My routine and preparation is something I really take pride in. . . . I was always the smallest guy on the mound, but my dad always told me, ‘You’re going to hit that growth spurt.’ Once we didn’t worry about that, I was able to focus on my mechanics, the mental side of my game. I was kind of able to grow as a pitcher in that respect for a lot of years before even coming [to Vanderbilt].”

Jack is a relaxed guy by nature, though he admits his demeanor on the mound is at least partially a learned behavior. Both on off days and on the hill, there is a clear intention behind each of Jack’s actions. Coaching him requires little dictation; Vanderbilt head coach Tim Corbin calls him “one of the easiest kids I’ve coached.” Pitching coach Scott Brown notes Leiter works with him more as a collaborator than a pupil, with a “constant conversation” occurring between the pitchers and their coach.

Rocker received a different training than Jack, though his path to Vanderbilt was similarly rigorous. Rocker’s dad, Tracy, was a two-time All-America defensive tackle and the 1988 Outland Trophy winner at Auburn, adding a pair of seasons in the NFL before kicking off a three-decade coaching career. Tracy has served as a defensive line coach at six SEC programs, and he’s now the defensive line coach with the Philadelphia Eagles. “Coach’s son” may be a cliché, but it’s very real for Kumar.

Rocker has won 11 of his first 12 starts this season :: David E. Klutho/Sports Illustrated

“He cares about the way things are done. He wants to be on time; he remains focused on his goals,” Tracy says. “He’s not perfect, but he knows what it’s like to be a leader on good days and bad.”

For Corbin, the fondest memory of Rocker’s no-hitter actually came 12 hours after he dominated the Blue Devils. Rocker had saved Vanderbilt’s season the night before, tying the Super Regional at one game apiece and setting up a winner-take-all Game 3. Highlights of the performance—all 19 of his strikeouts were swinging, and all came on offspeed pitches—were all over SportsCenter and Twitter, but there was no hangover for the team’s ace. “He was next to me the very next day hitting fungoes to the infielders. And he’s got a bucket of balls, and he’s feeding me one-by-one,” Corbin says. “There was no talk of the no-hitter, no nothing. His focus was, We have to get our team to the next game.

“Recovery from losing is one thing. Recovering from winning is another. Can you drop those moments? Can you understand that the very next day, those are the moments that actually define where an individual is going to go? I was so thankful to see a kid drop the experience he had last night and move forward.”

For much of his youth it was assumed Kumar would be a standout defensive end, but he stuck with baseball as well as football into his teenage years. He played a lot of third base, looking like a mini version of Aaron Judge or Giancarlo Stanton at the plate. The idea of pitching arrived almost by accident. Kumar and his mom, Lu, were at a travel tournament when Kumar was 15, and the 16-year-old squad needed a starting pitcher. Kumar took the mound on a whim and started fanning batters with a fastball that caught the eye of coaches and scouts.

“Kumar showed up and hit 89, 90 on the radar gun,” Lu says. “He wasn’t on the roster. All the coaches started scrambling, asking, ‘Who is this kid?’ I heard a mom behind me saying, ‘Ding ding ding, there’s a college scholarship right there.’ ” Kumar moved to the mound full-time shortly thereafter and dropped football following his sophomore season. There were no qualms from Tracy, who Kumar says “recognized my path before I did.”

Both Rocker and Leiter were drafted before coming to Vanderbilt, though both went far later than they would have had they not made it clear they did not intend to sign. Rocker was selected by the Rockies in the 38th round in 2018; the Yankees took Leiter one year later in the 20th. And while it’s certainly possible that both would have successful careers had they signed contracts out of high school, both scoff at the idea of being ready for professional baseball before college.

“Before I came here I didn’t really know how to pitch instead of how to throw,” Kumar says. “Freshman year I went to coach Corbin’s office and he told me, ‘Don’t ever let the game speed up on you.’ He put it into words, and it just clicked. . . . I’ve always liked my stuff, but here I’m growing mentally more than anything.”

At five, Jack hung with his dad’s Yankees teammates Derek Jeter and Gary Sheffield, while 11-year-old Kumar saw his father win the 2010 BCS title / Courtesy of the Leiter Family; Courtesy of the Rocker Family

There’s a consistent interplay between Rocker and Leiter, one that’s been present since Leiter’s first days on campus. Each long-toss session is littered with tips and tricks on different grips and arm angles, with collaboration taking precedence over each pitcher’s notable competitiveness. There is no debate over who is the team’s true ace, no jockeying for attention in the national spotlight. If they have spent the year battling one another for the top pick in the 2021 draft, you’d never know it by watching them. “They both really work to celebrate one another,” Corbin says. “There’s no drama. It’s about doing this together. They’re about the same thing: driving this team as far as it can go.”

Despite the consistently high expectations in Corbin’s program, there isn’t a rigidity at play like you might expect from, say, Nick Saban at Alabama. Vanderbilt is more like college baseball’s top Montessori program, with mornings in the fall featuring classroom lessons unrelated to baseball. This isn’t an occasional chat with the players, either. Corbin—a longtime Clemson assistant who took over a Vanderbilt program in 2003 that had made three NCAA tournament appearances and has since led the Dores to 14 berths in a row—creates lesson plans before each day, leading Socratic seminars on various aspects of the adolescent experience. Corbin details what it means to be a good husband and father. He and his players address issues of racial injustice and police brutality. “I think you become a much better person than you do a player,” Leiter says. “That’s been the most important thing about coming here.”

While Corbin is a philosophical coach by nature, the Dores are definitely on the cutting edge. “You run across a lot of guys in this industry that are ‘old school’ or whatever, but coach Corbin is as adaptive as any guy I’ve run into in this industry,” says the program’s director of player development, Brandon Barak. “He never turns down a chance to learn. I think that’s a part of why he’s so great. He has a real hunger for it.”

Edgertronic cameras and Rapsodo devices now track pitches at more than 1,000 frames per second, providing a detailed visual of a ball’s tumble to the plate. A ground-force mound helps pitchers maximize their velocity, assessing their drive downhill with their hips and legs. Barak and Brown work to convert the waves of data into digestible nuggets of information for Rocker, Leiter and the rest of the pitching staff, working to aid rather than overwhelm. Leiter uses the data to assess the spin rate of his curveball. Rocker works to increase the break on his new-found cutter.

The marriage of the technical and holistic approaches has worked wonders, and not just for Corbin’s current squad. Twenty-two Vanderbilt pitchers have been drafted in the first four rounds since 2007, with 10 going in the first. Leiter and Rocker are virtual locks to become Nos. 11 and 12 turned out by the Commodores’ factory. “You get consistency out of them in every facet of their life,” Corbin says. “They’ve put themselves in a position to be really special.”  

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