Kumar Rocker finally hits the majors

Anyway, let’s take another look at the Super Regional no-hitter.

This is Kumar Rocker at the peak of his career: A 19-strikeout no-hitter in the NCAA Tournament. (And hey, look, that’s Joey Loperfido!) Watching this video, you’d think he ran to the mound that night in Nashville and made the Duke lineup hit every single 59-foot slider he threw. You’d be right. Peak Rocker was one of my all-time favorite college players because he had everything you could want in an athlete. He was big, he was physical, he was talented. Watching him was like watching an excited teenager (which he was) manipulate the body of a major league ace (which he had).

Pitchers like him are rare, guys who not only mow down college hitters, but do so in a way that makes you wonder how even the pros can handle it. Stephen Strasburg, Gerrit Cole, Carlos Rodón, Paul Skenes and Rocker.

The direct path to the major leagues wasn’t so straightforward in the end. There was COVID, and Jack Leiter emerged as the better Vanderbilt pitching prospect, and there were concerns that Rocker might stagnate. After all, this was a kid who never should have made it to college in the first place, who more or less figured out the game as a freshman, won a national championship, and was named the College World Series’ Most Outstanding Player along the way.

Then Rocker let Brady Aiken hang on to the Mets, spent a year in the wilderness of independent baseball, and then was drafted again in the first round, this time by the Rangers. The last time I saw Rocker pitch was in March 2023. I happened to be in Arizona for the World Baseball Classic and accompanied Eric Longenhagen to watch Jacob deGrom and Nathan Eovaldi make simultaneous minor league rehab starts on adjacent backfields at the Rangers’ facility in Surprise.

Rocker was just starting a minor league spring training game again, and his slider looked fantastic. It bit and dipped and baited and deceived A-ball hitters, many of whom were frankly inferior to the competition Rocker had dominated in college. But that was where the good news ended. Rocker was throwing just over 90 mph and couldn’t locate his fastball or slider. He looked broken. Two months later, Rocker underwent Tommy John surgery.

It’s easy to forget the annoying fact about can’t-miss talent: They constantly miss their chances. I began to worry that Rocker might go down in history as a legendary college player whose pro career was derailed because it began three years later than it should have.

Don’t worry. Rocker will make his major league debut tonight against the Mariners.

It comes a little late — Rocker is almost 25 now — although the Rangers never let him waste a single pitch more than necessary in the minors. Since returning from Tommy John, Rocker has made just seven starts in Double- and Triple-A, pitching a total of 29 2/3 innings. In that time, he has allowed just 13 hits, three earned runs and four walks, while recording 47 strikeouts.

Rocker’s two Triple-A starts were tracked and entered into the Baseball Savant database, and the results are revealing. His four-seamer has an average velocity of 98.1 mph and a max velocity of 99.9 mph. He also throws a 90-plus mph sinker and a 90-plus mph changeup, both of which feature about 15 inches of arm movement. This highlight video from Rocker’s first Triple-A start includes a daring right-on-right changeup for a swinging strike.

That leaves the slider. That’s the pitch that Rocker threw most often in these two appearances: 55 of the 132 pitches he threw.

A few weeks ago I was pretty unkind to the Slider as a pitch class. After comparing other secondary offerings to precise, sophisticated art tools, I said the Slider was like a crayon.

It turns out that some artists can do a lot with a box of colored pencils.

In those Triple-A starts, Rocker threw 55 sliders, and opponents struck out 31 times. Eighteen of those 31 pitches were outside the strike zone, and 23 of those 31 at-bats ended in a miss.

I don’t really know how to categorize a 74.2% whiff rate, even in a two-start sample. The best I can do is this. The highest whiff rate on any pitch in baseball this season (at least 100 pitches) is Mark Leiter Jr.’s splitter, which produces a swing and miss 58.6% of the time. (Rocker really can’t escape the Leiter family, even in random statistical comparisons.)

Of course, a splitter is not a slider, and Triple-A is not the major leagues, but pitches with high whiff rates are usually chase pitches — either the batter swings and misses or sets the pitch down for a ball. Looking only at whether the pitch results in a strike, either by hitting the zone or generating a whiff, Rocker is ahead of the league’s best swing-and-miss pitcher.

It’s virtually unheard of for a single pitch to generate a strike-plus-whiff rate of over 50%. Anything over 40% is elite. According to Baseball Savant, only five pitches were thrown 50 or more times in Triple-A this season and generated a CSW% of 50% or more. One of those is Rocker’s slider. One of the others is Blake Snell’s curveball.

I’m trying really hard not to get too carried away with Rocker again. He has virtually no minor league track record, and whatever his talents, major league hitters are stronger, faster, and smarter than anything Rocker has ever faced. I don’t know if he can sustain the effort of throwing 90 pitches a game every five days. He’s had trouble maintaining his technique — many of the problems he faced both at Vanderbilt and early in his professional career had to do with dropping his delivery point.

None of that is enough to dampen the excitement of what is happening now. Rocker is making his major league debut, fresh off a blistering run through the upper minors that saw him gas at over 90 mph and throw an unhittable breaking ball. This is an event that I considered a near certainty from about April 2019 to June 2021, and over the three years since then, I have increasingly given up hope of ever witnessing. Now that it is actually happening, you don’t want to miss it.