Triston McKenzie is sliding his way to success

The jury is still out on just what Triston McKenzie will end up being for the Cleveland Guardians.

Two seasons into his major league career, McKenzie does certainly have a role in the rotation and has shown some level of effectiveness. He’s still “turn sideways and you’ll lose sight of him” skinny, but the velocity seems to have leveled out to somewhere around league average, if not a bit more. Which is great! Cleveland has a decent track record of helping other pitchers add a few ticks on the gun here or there, and considering he’s still just 24 and should fil out a bit, it’s certainly possible for McKenzie, giving him a nice ceiling to look forward to.

For now, though, he’s somewhere like a third or fourth starter in a decent rotation, which is where he finds himself. And while he’s being used as a combo starter/piggybacker, it’s plain the long-term role for the season is his collecting 25-30 starts, as long as his arm holds up.

In his seven innings of work as of this writing, McKenzie has been very effective, despite his throwing nearly 70% fastballs. That, and the uptick in velo we’re seeing, are certainly a result of his being only half a starter right now, but so far it’s working. Aside from the four-seam though, his judicious use of a slider has really been a great equalizer for him.

It’s not really a new thing. McKenzie has thrown about 20% sliders each year and gotten solid results even if Baseball Savant sees it as little more than a middle-of-the-road pitch. Between 2020 and now, he’s averaged out to a run value of exactly zero, meaning it’s been neither good nor bad. What’s especially interesting this year — albeit in a small sample size — is the uptick in velocity we’re seeing from that slider. In each of the last two seasons, he’s thrown it at 86.3-86.4 mph, a shade above league average. This year, we’re looking at a velo bump to about 88 mph. While that’s not some earth-shattering, explosive leap, it puts him in the top 10 among starters. That’s something to raise an eyebrow or two.

Moreover, a key to his success, especially if his fastball velo doesn’t move much, is how those two pitches pair. The slider isn’t elite in movement, just 1.3 inches of horizontal movement better than average, and more than six inches of vertical movement less than average, but paired with the fastball it works into a wonderful 1-2 combo. That roughly four to five mph of velocity is just enough to hide one within the other, meaning the hitter is immediately on the back foot.

Like, here’s his slider by itself:

Not overly impressive. Not some kind of hellish sidewinder like Andrew Miller, and certainly not the silly slurve of Corey Kluber. We’ve seen cutters with more obvious bite. It’s got tight, late movement, and that’s about it. Paired with his fastball though, and suddenly you’ve got something cooking:

Aristedes Aquino isn’t a superstar of plate discipline, but he got rocking back and forth on that one and didn’t look happy at all. It’s more than the whiffs though, McKenzie can use this combo to create soft contact, keep hitters generally off-balance, and once he starts folding his curve and change into the mix, suddenly you have a lethal repertoire.

It reminds me a bit of Zach Plesac actually. Both have solid if unspectacular four-seams, and a slider that, again, isn’t elite in any stretch, but they make it work. The tertiary parts of Plesac’s attack plan include a changeup, but at least this year he’s a step behind McKenzie in the velocity department. And yet, to this point, he’s been incredibly effective.

McKenzie is bound to start throwing fewer fastballs — 69% is pretty absurd if you want to get through a batting order two or three times — and this is part of that recipe. He’s got a really strong curveball too, which we’ll talk about another time, and flashed a change against lefties last year too, so there’s certainly a lot to continue to unpack with him. It’s neat to watch this evolution of pitcher; how he gets his own tools to work for him.

He’s far from a finished product, but he has the tools to become much more than we’ve seen already. As with so much involving McKenzie, we will watch these developments with great interest.