Brent Suter Is at It Again. Bring a Mop and Bucket.

Back in March, I used the Rockies’ signing of Brad Hand as an entry point into an interesting trend: the Rockies were stockpiling soft-tossing lefties. A couple weeks later, I went to Scottsdale and talked to Austin Gomber. And now I’m writing about the Rockies’ pitching staff again. And not their erstwhile no. 1 starter (Kyle Freeland) nor their closer (Pierce Johnson) nor the guy who was supposed to be the closer (Daniel Bard) nor the hard-throwing setup guy with the goofy slider (Justin Lawrence). I’m writing about Brent Suter, another finesse lefty. The most soft-tossin’ lefthander in all the land, as a matter of fact.

Why? Because I can, mostly. If you’re tired of reading about the Rockies’ bullpen, write your Congressperson. They can't stop me either. But also because Suter seems to have cracked it. This 33-year-old, whose fastball is so slow passing motorists would give it the finger for holding up traffic in parts of Texas, has been one of the best relief pitchers in baseball this year.

Among qualified relievers, Suter is seventh in WAR and fourth in ERA despite playing in Coors Field. He has not allowed a home run this season, despite, again, playing in Coors Field. He's also pitching a huge volume of innings; 30 2/3 is the third-most among relievers. (Teammate Jake Bird is second, so maybe Bud Black is just indulging his inner Davey Johnson.)

Suter is matching Josh Hader in performance this season for one reason: Nobody can square him up. Normal caveats about the Baseball Savant Patriotic Lollipops in mind, take a look at this:

This is one of the funniest graphics you’ll see all season. Suter is working in a velocity range that would’ve gotten him laughed off the mound in the mid-1990s, and yet out of 379 pitchers on Baseball Savant's leaderboard, he has the fourth-lowest exit velocity, the second-lowest HardHit%, and the fourth-lowest barrel/PA ratio. It's like he's sneaking into the other team's clubhouse before the game and covering everyone's bats in soap.

Looking at Suter's repertoire, you’ll find four pitches: a four-seamer, a sinker, a changeup, and a slider. And if you know anything about how pitchers (particularly relievers) use their secondary pitches, you can probably guess how the change and the slider interact. Suter has thrown 127 changeups this season, 121 to right-handed hitters, and he's thrown 39 sliders, 37 to left-handed hitters. The fact that he's thrown so many more changeups than sliders is based mostly on the fact that he's faced almost twice as many right-handed opponents as left-handed. Curse the ancient and outdated norms against allowing left-handed children to write with their left hand.

It will also not surprise you to learn where Suter is throwing his secondary pitches. The changeup, which breaks away from right-handed batters, is thrown almost exclusively on the outside corner. Of those 121 changeups to righties, only four have ended up on or near the inside edge of the zone:

Put the changeup in a mirror, and you’ll see how Suter has used his slider: Low and away to left-handed hitters.

I’d like to take a moment to talk about Suter's slider, because it's a very funny pitch. Baseball Savant's leaderboard counts 307 pitchers this year who throw a slider. Of those, Suter's has the third-slowest average velocity. Not to get into "what the heck is a slider anymore" again, but the hardest slider belongs to Hunter Brown. If you had two pitching machines, one calibrated to the velocity of Suter's slider and the other to Brown's, and you fired them at the plate at the same time, by the time Brown's ball crossed the plate, Suter's would be 10 1/2 feet behind.

Over the course of a baseball's journey to home plate, a slower-moving pitch will drop more than a faster one because gravity has more time to act on the baseball. Add in that Suter's slider already has a lot of vertical break compared to pitches in a similar velocity band, and you get the hardest-dropping slider in baseball by a huge margin: 51.6 inches between release and home plate, 2.9 inches more than second place. Only 10% of sliders in baseball are within 10 inches of his in vertical movement.

Surely, then, this is a pitch that disappears out of the zone and gets swung over and missed, yes? No. Suter has thrown 39 sliders this year; of those, 24 were taken for balls. Batters have swung at Suter's slider (and "Suter's slider" is starting to sound weird so I’ll wrap this section up soon) seven times and made contact every time: four foul balls and three weak fly outs, none coming off the bat harder than 80.8 mph. Of the 204 sliders he has thrown in the big leagues in the past three seasons, only three have been turned into base hits, the most recent of those in July 2021.

In general, Suter has been going to his offspeed and breaking stuff a little more in 2023 than in years previous, but the biggest change in his repertoire has been a new emphasis on the sinker. Up until this season, his primary fastball was a four-seamer; the sinker was a show-me pitch at best, thrown only a few dozen times per season. This year, he's thrown them in roughly equal proportion to both right- and left-handed batters: 155 four-seamers, 147 sinkers.

The difference between the two pitches is subtle; the sinker averages about 88 mph, the four-seamer a couple ticks shy of 86. In terms of vertical movement, they’re nearly identical, while the sinker carries a few more inches of horizontal movement. Visually, I’ll be honest: I have trouble telling the difference between the two. Here are consecutive pitches from Suter's last outing. First, the four-seamer:

And then the sinker:

The movement on the sinker allows Suter to explore more of the strike zone. With his four-seamer, he tends to go up and in to right-handed hitters, exaggerating the natural left-to-right movment generated by his delivery. The sinker he’ll throw anywhere, giving hitters more of the zone to cover.

Suter is a hard guy to pin down anyway because his delivery is so weird and his arm slot is so low; glove-side cut and arm-side run are going to look a little different out of his hand. Then you have to factor in that the difference between the two pitches is essentially only a few inches in lateral movement. A batter who thinks he's swinging at a four-seamer will probably still make contact with the sinker, just not on a profitable area of the bat.

Last season, opponents hit .307 and slugged .536 off Suter's fastball, which was a bad time for the big lefthander, because he threw his fastball 65.1% of the time. This season, his whiff rate on his four-seamer has actually dropped, and the batting average against the pitch has only fallen to .270. But hitters are slugging just .324 against his four-seamer, and .200 against the sinker.

Suter's ability to dodge hard contact has put him up on various leaderboards with guys who do their job the old-fashioned way: Chasing whiffs. And as much as I think it’d be fun to throw devastating offspeed stuff and strike out 15 batters per nine innings, there's a mischevious potency to how Suter pitches. It almost seems inelegant to strike batters out when he's up there pulling quarters out of their ears, making them forget where they parked their car, breaking into their homes at night and hiding all their spoons.

They say pitching in Colorado is a hard job, and it is. But Suter is being paid $3 million this year to screw with hitters’ heads. That sounds like a really fun gig to me.