Mariners Ostensibly Take a Flyer on Bryan Shaw

As more time passes, it seems like more of a sure thing that Bryan Shaw is, in fact, going to be a Seattle Mariner. So I guess we should talk about it. As the story goes, Shaw had something of a breakout in 2017 before enduring two straight negative WAR seasons in 2018 and 2019. The Mariners’ hope, I presume, is to help him turn it around and bolster a youth-laden bullpen.

If you’ll remember, the Mariners had a pretty miserable bullpen last year. Aside from Austin Adams (who looks to be a bona fide bullpen ace) and Matt Magill, the bullpen was grim. By WAR, they ranked 27th in the league, and 22nd and 24th in ERA and FIP, respectively. Even if he turns out to be a shell of his former self, Shaw checks all the boxes a rebuilding team needs. He’s proven that he’s good for 60 or 70 innings a year, and so the Mariners will look to ride him so as to not wear down the younger guys and use him to replace pitchers who have gone down with injury. Oh, and he’s a veteran presence, which does and does not matter.

Now that Shaw is one of our own, we probably ought to figure out what’s been holding him back for the past few years. Some answers are more obvious than others:

The relationship isn’t super clean, but it’s intuitive to think that when Shaw stopped throwing so hard, hitters started barreling up his pitches more. After all, even though his cutter is a swing-and-miss pitch relative to most fastballs (namely in 2017), it gets put into play a fair amount — as is the nature of cutters. Part of that reason is because he wasn’t getting hitters to put his cutter on the ground as much. His ground ball percentage fell from 58.0% in 2017 to 49.7% and 52.3% in 2018 and 2019, respectively.

Here’s his cutter in action:

It’s not like he had a Kenley Jansen cutter before. Jansen throws a cutter that gets the ride of a four-seam fastball, but it cuts to his his glove-side instead of his arm-side. It’s a generational, unicorn pitch. Shaw’s 2017 certainly falls short of generational, but it was good.

For Shaw, his cutter may not have been special to the extent that Jansen’s is, but it was special in its own right. Aside from Emmanuel Clase, Shaw’s cutter in 2017 is the hardest cutter in all of baseball. Its .304 xwOBAcon and .286 BABIP in 2017 may have been too good to be true, but it was truly a legitimate pitch. It’s already hard enough to hit a pitch that’s thrown 94 mph. Add in that it drops less than a typical cutter and has above-average horizontal movement too, and it gives hitters a really unique look that’s tough to barrel up. That’s why he missed bats, and why he induced so much weak contact.

Now, in the past two years, it’s been a different pitch. You’ve already seen that’s he’s been hemorrhaging velocity, but the composition of his cutter is changing too. Consider the following:

While velocity and movement are related, one of the things that made Shaw’s cutter unique was that it dropped less than the average cutter. Now that his velocity has decreased, it’s about league-average in terms of vertical break. It’s a heavier pitch now, and it’s lost most of its uniqueness, which means that we probably shouldn’t be surprised that it’s getting hit hard since he throws it three-quarters of the time.

Again, velocity is playing a role here, but perhaps some of the reason that his cutter is getting extra drop now is because he’s converted his vertical movement into horizontal movement. Shaw’s horizontal movement on his cutter, since 2016:

Compared to before, Shaw has added some horizontal movement to his cutter. It may look insignificant, but this is the most horizontal movement he’s had on his cutter in his career — and he’s had a long career. There’s no tangible reason that I can see that this is happening. It doesn’t seem like it’s due to a change in arm slot, so perhaps he’s getting on the side of the ball more.

In any case, in 2017, Shaw wielded the hardest cutter in baseball. Last year, he still threw a hard cutter, but he’s been usurped by several other pitchers in velocity. All of the things that made his cutter unique have eroded with his loss of velocity, and he’s left with a cutter with plus velocity (relative to other cutters), average vertical movement, and a touch more horizontal movement than is average. In other words, it’s a pretty ordinary pitch now.

Now, it may seem impressive that his cutter ranks in the 93rd percentile in velocity, but in actuality it’s, well, not. Because his cutter doesn’t get a lot of ride, he’s essentially throwing a sinker. The difference is instead of breaking to his arm-side, it breaks to his glove-side. So, unless he gains two ticks of velocity back or adds horizontal movement to his cutter (adding drop wouldn’t be good), he’s left with a mediocre pitch.

At this point, there isn’t much of a precedent for Shaw’s skill set prospering; especially if his cutter has departed for good. There’s a short list of pitchers that almost exclusively throw cutters, and of the ones who do, Shaw’s is probably the worst. Even at its best, his cutter’s peripherals look more like that of a good fastball than an elite cutter like, say Álex Colomé’s or Jansen’s.

Odds are, I just spent this time writing an article about a journeyman whose best days are behind him, rather than a player that a saber-savvy organization feels like they can help restore. My gut says that the Mariners are more interested in a reliever that can eat innings as opposed to them seeking a reliever that they can remedy. Of course, the two aren’t mutually exclusive, but it’s far more likely that Shaw is more 2018 and 2019 than 2017. And for the Mariners, that’s just fine.