Nothing against the exciting potential in the arms of Mets second and third round picks Calvin Zeigler and Dominic Hamel, but the 2021 draft will always be remembered by Mets fans as the day Kumar Rocker surprisingly fell to their team in the first round. Finally, seeing the 21 year old Vanderbilt star put on the orange and blue became reality.

But exactly what kind of feelings that memory engenders five, ten, fifteen years from now has hardly been determined. This – Kumar Rocker’s professional development – remains unwritten, and will be the focus of both the pitcher and the Mets minor league pitching program. Under the leadership of Ricky Meinhold and Carter Capps, the goal is to actualize the young stalwart’s full potential.

But everything starts with acquiring the best possible piece of clay, for the development process is only a molding and tweaking process. With relatively rare exceptions, the underlying talent should already be visible from the get-go. Luckily for Kumar Rocker, his prodigious 6’5″ 240 lb frame exudes that talent in spades. Aside from putting up huge numbers in the SEC for three seasons against the best competition college baseball has to offer, today we’re going to look at Rocker’s immense talent from a more visual and qualitative and analytical perspective.

The Fastball

For most pitchers in today’s game, the foundation almost always needs to start with a fastball that can consistently do one of two things (or preferably both): garner swings and misses and generate soft contact on the ground. Thanks to modern technology and studies done on spin metrics and movement, we can often predict which fastballs will do these things better. So where does Kumar Rocker’s fastball fit in on this spectrum?

On the one hand, the velocity of a fastball is at least half of the battle. But that’s hardly the only factor that goes into a fastball’s effectiveness, and really, when you look at all of the components of Rocker’s four-seam heater, the total output is promising, but not entirely clear at this point. Let’s break his fastball down into the three key components: velocity, command, and shape.

If you look at the totality of Rocker’s amateur career, his fastball has fairly consistently sat in the mid 90’s since he was an upperclassman at North Oconee High in Georgia, peaking as high as 97-99 mph on a few occasions at Vanderbilt. So in that sense, there is plenty of hope to project Rocker to feature plus velocity on his fastball, even by today’s standards. Rocker has plus arm speed and uses his powerful lower-half to drive off the mound well and get great extension, providing every reason to believe plus velocity should be coming from his linebacker-esque build. But for some reason, that hasn’t quite always been the case, especially during this past draft season. It’s one of the primary reasons Rocker was even available for the Mets to pick 10th overall.

In many of Rocker’s starts for the Commodores in 2021, Rocker’s fastball would sit in the low 90’s, peaking at mostly 93 mph. In other starts, Rocker would sit 93 mph, and reach back for 95 or 96 on occasion. In Rocker’s final start of his illustrious Vanderbilt career against Mississippi St., he sat in the low 90’s with very inconsistent command. The hypothesized reason for Rocker’s inconsistent velocity is mostly mechanical inconsistency with his delivery, something which will surely be a focus in his professional development with the Mets.

The other nit-pick that teams at the very top of the draft this year were said to have questioned about Rocker was his fastball command. Rocker has generally been very adept at filling the strike zone with his four seamer, but many scouts call it control over command at this point. Developing a more consistent ability to hit his spots with precision will also come down to the Mets helping Rocker fine-tune his delivery and achieving greater repeatability. But fastballs with exceptional shape can more often survive non-ideal strike-zone placement, so that brings us to the final component of Rocker’s fastball: what kind of movement profile does it have?

The shape, or movement profile, of Rocker’s fastball has also taken some mild criticism from some, likely, more progressive front offices. His fastball does not precisely feature the huge carry that accentuates the ability to get swings and misses at the top of the zone, at least when compared to his former-teammate Jack Leiter.

But Rocker’s fastball is not of the sinking variety, as he does achieve 18.2 inches of induced vertical break (IVB), which is a surrogate measurement for carry and is slightly above average. With an arm slot that enables a spin axis close to 1:00, Rocker also gets some good run on his fastball. Combining this with the good extension he creates with his delivery, I think you’re looking at a fastball that has the potential to have plus velocity, good shape, and fill the zone with adequate location considering the strength of the first two traits. Check out the carry on Rocker’s fastball at its best at the beginning of the clip below.

Kumar Rocker is back, baby. Strikes out every batter he saw in the first inning.

Commanded a mid-90s fastball at the top of the zone brilliantly that inning, threw a few nasty back-door sliders along the way.

Game on. #MLBDraft pic.twitter.com/whY2nqrGmN

— Joe Doyle (@JoeDoyleMiLB) February 22, 2021

The Slider

The final strength of Rocker’s fastball is that it plays very well off of his signature go-to pitch, a devastating slider. Rocker’s slider, if not his fastball then, is the prototype of today’s ideal breaking pitch. It comes in hard, usually in the mid 80’s, and features primarily late-breaking vertical depth, enabled by it’s significant gyroscopic spin. It works akin to a curveball, tunneling well off of the four seam fastball, but with more velocity than a typical curve. In the famous no-hitter that Rocker threw against Duke to win the College World Series in 2019, the slider was the feature presentation. You can see the extreme depth he gets on the pitch below.

NO-HITTER.
19 STRIKEOUTS.

VANDERBILT’S KUMAR ROCKER JUST MADE HISTORY! pic.twitter.com/Q05eYikbbR

— SEC Network (@SECNetwork) June 9, 2019

 

Rounding it Out

While Rocker’s fastball-slider combination was his $6 million bonus money-maker, the Mets development team will be looking at a third and fourth pitch to round out a starter’s repertoire, and Rocker comes with two promising beginnings underway.

Rocker did not throw a changeup very often as an amateur, typically out of lack of necessity, and he does need to work on getting comfortable locating it down and away from left-handed hitters where they cannot do much damage against it. According to Lookout Landing’s Joe Doyle, Rocker does get good fade on the pitch and achieves a solidly low 1700 rpm, enabling gravity to help pull it down late in it’s flight. The Mets had great success helping Matt Allan hone his changeup as a third valuable weapon, and will surely look to do the same for Rocker.

Meanwhile, Rocker did work pretty heavily on a cutter in his final season at Vanderbilt, working the pitch in the upper 80’s and featuring late, tight horizontal movement to his glove-side. It will be interesting to see whether the Mets and Rocker end up choosing to eliminate or feature this pitch in his professional repertoire.

At the end of the day, many fans might hear the name Kumar Rocker and have expectations of the next great Mets front of the rotation stud pitcher. The talent and tools are certainly there for that to one day come to fruition. But hard work and development lies ahead for Rocker and the Mets in order to fulfill that potential. With Rocker already reportedly having agreed to his over-slot bonus, everyone is excited and watching, ready to see the Mets and Rocker get to work and make his potential future stardom a reality.