Let’s talk about Logan Gilbert’s debut

Logan Gilbert has passed the eye test

I can’t remember the last time that I watched the Mariners and it felt special. Perhaps a time or two in the past decade or so, when they’ve flirted with their first playoff berth since 2001. If it wasn’t then, it was probably when the Mariners lured Robinson Canó to Seattle (even if it took a quarter-billion-dollar contract over 10 years). For the first time in a long, long time — and maybe ever, for me — the shared debut of Logan Gilbert and Jarred Kelenic not only made me feel optimistic about the future, but across the country, many eyes were on the Mariners. So last night? It was awfully special.

I’ll say, it wasn’t a particularly close game. I mean, Zach Plesac flirted with a damn no-hitter! But the two rookies flashed promise, and that’s what matters. Of course, I’m not here to talk about Kelenic. I’m sure he’ll get his own article before long. I want to talk to Gilbert, because, despite the runs he surrendered, he looked every bit the part of a major league pitcher, and had moments of an overpowering one.

To start the game, here’s what Gilbert’s pitch mix looked like in the first inning:

• Fastball
• Fastball
• Fastball
• Fastball
• Fastball
• Fastball
• Fastball
• Fastball

Needless to say, Gilbert didn’t feel the need to mix it up much, and for a rookie debuting in his first game, I’m not sure he should have. The result was eight pitches: one called strike, one whiff, and three weakly hit balls to Mitch Haniger and Kyle Lewis.

Here’s one of his first eight pitches of note, a fastball to José Ramírez:

If Gilbert is to be the pitcher that many envision him to be, it all starts with his fastball. This is a 96 mph fastball with just nine inches of vertical break, his second-lowest of the night. For those without a strong frame of reference, that’s a whole lot of fastball ride, and when it’s located well up and inside, there’s not much Ramírez was going to do with this. Especially when Gilbert is getting over seven and a half feet of extension on his fastball.

Ramírez ended up getting the best of him on a fastball later in the game:

With an exit velocity just under 96 mph, it’s certainly not the hardest-hit home run, but Gilbert shot himself in the foot by working into an unfavorable 3-1 count, and missing his spot glove-side. These are the mistakes that get punished at the major league level, and ones that will cease to hamper Gilbert with regularity once he gets the kinks worked out.

The fastball, overall, was pretty much as expected for a debut. Its overall 23% CSW was low, but with improved location will come improved results. What I was keeping my eye on was how Gilbert’s secondaries played. Given that I haven’t had the opportunity to play around with the data, I was excited to see his pitch mix and how the numbers on his pitches bore out.

Here are Gilbert’s scouting grades, per beloved Lookout Landing alum, Nick Stillman:

Now, what is perhaps most interesting to me is Gilbert’s curveball. It consistently gets better grades than his slider despite being, in my opinion, an inferior offering. That seems to be a common scouting issue with several pitching prospects. Players with softer, loopier curveballs with a lot of drop are aesthetically pleasing, and scouts fall in love with them. I liken Gilbert’s slider-curveball combo to that of Dylan Bundy, Max Fried, and Clayton Kershaw: All were renowned for their curveballs coming up through the minor leagues, and yet all of their best secondaries ended up being their sliders. I had this conversation this morning.

Here’s Gilbert’s first non-fastball of the game, an 0-0 curveball to Franmil Reyes:

Given that he’d thrown 12 straight fastballs, it’s reasonable enough for Reyes to think that this is a pretty tough fastball to hit at the top of (or above) the zone, but it dies and falls into the zone for a strike. This, to me, is the best use for Gilbert’s curveball. The term “get-me-over” is often used as a pejorative, so perhaps a better way to frame his curveball is as a strike-getter, or strike-stealer. When he’s throwing a firmer curveball, it moonlights as a whiff pitch and chase pitch. But when it’s sitting 74 mph — as it was last night — its best use is to steal strikes in the zone.

What sits smack dab in the middle of his fastball and curveball in velocity is Gilbert’s slider. Here’s his first slider of the game:

Oops! Gilbert follows up the curveball with a slider in the middle of the plate and Reyes rips it 111 mph off the bat and gives it a ride over the fence in center field. Gilbert struggled to find his slider at times in the night. Perhaps a contributing factor is that he had two slider shapes last night:

pitch movement, by vertical and horizontal movement

That’s not meant to come across as causative, but to my eye, I think this has less to do with manipulating the shape of his pitches, and more to do with trying to find his slider. Notably, the differences in shape didn’t seem to vary by count or handedness. Gilbert is said to have trouble with this at times, and it seems to be the case here that his slider got slurvier on him at times, which will be something to continue to monitor.

It’s important to note that, unlike his curveball, he can get hitters to chase on his slider, even when they’re not located close to the zone. Here’s one out of the zone that he misses with arm-side but gets César Hernández with:

A second strikeout, that looks like it’s going to be a fastball, center cut, but ends up perfectly located at the bottom corner of the strike zone:

A third strikeout that Gilbert bounces on the chalk of the batter’s box on the left side:

A fourth strikeout that draws a sword from the left-handed Jake Bauers:

And a fifth strikeout that Gilbert bounces in front of the plate to get the out against Austin Hedges:

This collection of hitters isn’t exactly Murderers’ Row, but I do think it’s fair to say that Gilbert doesn’t need to have the best command of his slider every night. He just needs to keep the ball down. Gilbert only got punished badly once last night with his slider, but good hitters are going to take advantage of mistakes, and Gilbert threw more than a few mistake sliders.

This was just one night for Logan Gilbert, and there will be many more nights. He didn’t have his best stuff, but if you didn’t notice, he didn’t even break out his changeup, which is sometimes his best offering. The changeup will come out to play, the nerves will subside, and the command will tighten up. All of these things feel inevitable. If you weren’t reassured by Gilbert’s debut, I hope you’ve reconsidered his outing and perhaps tempered your lofty expectations for the first night of his young career.