40 in 40: Logan Gilbert seeks to become unpredictable

Feb 8, 2023 - 5:00 PM

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2022 was the year of the rookie for many teams, but in particular the Seattle Mariners. Julio Rodríguez obviously broke through and was crucial down the stretch, knocking clutch hits when it mattered, and was rewarded with a Rookie of the Year victory. Just as exciting was the emergence of George Kirby, another highly touted prospect who put on quite the performance for the M’s in the second half of the season. However, nestled in their shadows were the performances of post-rookie-buzz but still valuable homegrown players like Cal Raleigh and his batterymate and longterm teammate, Logan Gilbert.

The lanky right-hander started the season strong. He trounced teams in April, going 3-0 with a 0.40 ERA and an sOPS+ of 41 through March/April, among the best in the league and earning him his first AL Pitcher of the Month award in April. However, Gilbert wasn’t able to maintain this level of excellence all season. A particularly poor August (6.75 ERA/5.06 FIP) dragged his overall numbers down, although he was able to finish with a very respectable if not as-dominant 3.20 ERA. Meanwhile, teammate Kirby soared to become one of the most buzzed-about players in baseball, ending his season with a star turn in the ALDS.

But I believe there is more to come for Logan Gilbert that’s more in line with his April than his August. We have seen Gilbert take great strides forward in his pitching, and while he may not be the out-and-out ace of the staff, he still possesses head-turning stuff. Not only has Gilbert relied less on his fastball, and introduced a sinker, but he has also made his off-speed pitches much more impactful; both his changeup and his curveball have had significant jumps in effectiveness.

There’s no denying that Logan Gilbert has one of the best fastballs in the majors right now. In 2021, the fastball alone was worth a monstrous -19 runs (for pitchers, negative numbers are good); however, he leaned on the pitch extremely heavily: 61.5% of the time to be exact, and while the pitch is effective, no pitch is so effective it doesn’t get smacked around a little if you throw it twice out of every three pitches. This was further proven in 2022 when Gilbert's fastball took a bit of a step back. While he still threw it pretty often (53.9%), its effectiveness decreased to a -12 run value—still good, but a significant drop from 2021. However that being said, Gilbert was able to earn more whiffs on his fastball despite throwing it less, increasing both his put away and K% from 2021, with K% going from 21.9% to 22.5%, and the Whiff percentage going from 21.6% to 23.7%. Despite the drop in run value, if Gilbert continues to throw his fastball less and less, it’s highly likely that the batter will have a much more difficult time keeping up with it as they won’t simply be able to sit on his fastball in advantageous or neutral counts. This, of course, relies on his other pitches becoming more effective, and Gilbert may be developing something that would greatly increase the effectiveness of his fastball.

Late in 2022, Logan Gilbert added a sinker into his repertoire. Now I know what you’re thinking; you’re thinking, “Ezra, you handsome, amazing genius, how do you know it wasn’t a mistake pitch that Savant just picked up as a sinker?” Well, dear reader, mistake pitches don’t look like this:

Okay well, they do, but did you see that noticeable hitch or “hump” on it? Logan’s fastball doesn’t do that, as demonstrated below.

As you can see this is a much sharper pitch than the sinker and is also slightly faster at 97 miles per hour. Now, it's clear the sinker is still a work in progress; with Gilbert having only thrown it a grand total of 41 times in 2022, it’s difficult to say whether it's effective yet, but the early signs are good. Despite limited use, the sinker still registered a 25% hit percentage, better than the fastball (50.5%), curveball (48.5%), and slider (41.3%). Additionally, a very promising trait is how close in speed the sinker is to the fastball, with the sinker coming in at 94 MPH and the fastball at 96 MPH. When a pitcher has one dominant fastball, it can be valuable to focus on that pitch, however Gilbert’s four-seamer is a bit of a mixed bag despite his heavy reliance on it. Working in another pitch to utilize against lefty hitters in particular like a sinker is a potentially savvy improvement. With a whole offseason of development, I don’t see any reason why adding a sinker to a deadly fastball pitcher wouldn’t make Gilbert much more dangerous in 2023.

But the sinker isn’t Gilbert’s only area of improvement. Last year LL alum Michael Ajeto wrote that if Gilbert can improve his secondary pitches he will be “much more consistent and much less predictable” and Gilbert seems to have done just that. In 2021, Gilbert’s slider and changeup, while both whiff-getters, got consistently hammered when batters did make contact: a SLG of .460 on the slider and .682 on the changeup. In 2022, however, his slider and change-up have improved by leaps and bounds.

In 2021, Gilbert’s slider featured significant sweep, or horizontal movement, but he wasn’t able to command it consistently; it created a fair amount whiffs (38.6%), but was worth +9 runs (bad), with a 39.5% hard hit percentage, and an opposing wOBA of .310: not terrible but still not very good. Batters also slugged .460 off the pitch, with an xSLG of .462 suggesting they weren’t just getting lucky when they did find that pitch in the zone.

Prior to 2022, Gilbert worked on making the slider harder and more cutter-like, and during the 2022 season, he refined it even more to add more drop, a la Verlander’s slider. With those improvements, Gilbert has gotten the slider down to a run value of 0, a hard-hit percentage of 41.3%, and an opposing wOBA of .268. While those season-long numbers might not jump out, there’s a direct correlation between the months where Gilbert spiked his slider usage (almost doubling it from August to September/October) and the months where he had his highest K% of the season, striking out a over 29% of batters faced. While there is still obviously some work to do in terms of the hard contact being made when he misses his location, it's clear the pitch has gotten more effective.

Similarly, Gilbert’s changeup also took a great leap forward in 2022. From a run value of +6 in 2021 (again, bad!), the pitch went to a run value of -3 in 2022, dropping the wOBA on the pitch from .465 to .145, which is an insane amount of improvement on one pitch over the course of one off-season. A change in grip, which was noted at the start of spring training 2022, can help explain the improvement, as can locating the pitch consistently at the bottom of the zone, where it tunnels well with his new-look slider. However, those improvements came at the cost of some whiffs, maybe relegating the changeup to a distant fourth or fifth, change-of-pace pitch rather than the whiff-getter it’s looked like at times.

So Logan Gilbert, despite a rough rookie season and being overshadowed in his sophomore year, looks poised to take a huge jump in 2023. Becoming less reliant on his fastball, adding a sinker, and improving his off-speed pitches leaves Gilbert well-prepared to dominate opposing lineups in 2023.