Drew Steckenrider was for real, maybe is for real

If you’ve just woken from a deep slumber, welcome! The Mariners won 90 games last year! If you’re wondering if they made the playoffs, I think that’s HIPAA. (No, they did not.) To catch you up, the Mariners were the beneficiaries of a whole lot of luck, or whatever you want to call it, winning 12 more games than their Pythagorean record suggests they should have.

Perhaps nothing helped the team win than extremely, extremely timely hitting — their lineup ranked 27th in wOBA overall — but there’s also that they benefited from late-game heroics from their pitching, too. Regardless of your metric of choice — whether it’s ERA, fWAR, or WPA, you name it — the Mariners’ bullpen ranked favorably. Paul Sewald and the not-dead-but-departed Kendall Graveman get a lot of the credit for that, but Drew Steckenrider might be the most unsung hero in a bullpen full of them.

Steckenrider joined the team on a minor-league deal after a disastrous 2019 — he posted a 3.77 home runs per nine innings over 14.1 innings — and then sat out 2020 with a triceps injury. To say his expectations were low would be a helluva understatement, and yet, in terms of his outcomes, Steckenrider was one of the most reliable relievers on the team.

It’s important to consider why, but first, here’s how Steckenrider stacked up against the rest of the Seattle bullpen in 2021:

• IP: 67.2 (1st)
• ERA-: 48 (3rd)
• WPA: 3.07 (1st)
• REW: 1.90 (1st)
• WAR: 1.3 (2nd)

The results speak for themselves. In terms of going out there and getting it done, there’s an argument to be made that no reliever in Seattle’s bullpen was more valuable to the team over the course of the year than Steckenrider. Of course, I wouldn’t make that argument, given it would be missing a lot of key context, such as the team riding Sewald much harder over the stretch, or the respective leverage of the situations in which they were deployed.

And then there’s also that each pitcher goes about their success in much, much different ways — Sewald and Steckenrider finished the year with 30.3 and 15.4 percent strikeout minus walk rates, respectively — and so, for Steckenrider, it’s pertinent to consider how and why he stymied hitters.

As with most pitchers, his arm slot is instructive in understanding how he goes about getting hitters out:

Steckenrider throws out of a high arm slot with a fastball that’s certainly solid by raw spin and velocity, but not otherworldly. The thing about throwing a fastball out of this slot is that the margin of error is pretty slim. That is, the higher the arm slot, the higher one’s induced vertical break (IVB) needs to be to get plus ride, or enter the zone at a flat angle.

Consider how his fastball characteristics stack up against the league:

At 94 miles per hour, his velocity may not set him apart, but if you put all of his metrics together, they get him to an 18.7 IVB which, in a vacuum, is an elite fastball, but when you consider it with his high release slot, it’s more ordinary. That’s corroborated by the closest fastball comps for Steckenrider, who include Jeff Hoffman (2021), Erik Swanson (2019), and J.P. Feyerstein (2021) — a fairly mixed bag.

For fastballs, we know that, by vertical approach angle (VAA), a flatter fastball often means more whiffs at the top of the zone, and a penchant for getting hitters to take strikes at the bottom of the zone. Two of the main inputs for VAA are release height and extension — both of which Steckenrider does not grade out favorably — but another meaningful input is pitch height. And that’s where Steckenrider makes his money.

After any given pitcher releases a fastball, the ball travels to the plate at a slightly negative angle, and by the time the ball reaches the plate, the same is true. But what matters as much as the pitcher’s characteristics while releasing the ball is what happens soon thereafter: VAA is heavily influenced by pitch height. The higher in the zone, the flatter the pitch; the lower in the zone, the steeper.

Steckenrider elevates his fastball more than most relievers: he ranks in the 91st percentile by percentage of fastballs thrown in the top shadow zones, and there are a few things we can draw from that. First is that his average -4.6° VAA is much flatter than his zone-adjusted VAA, which means that, despite some of Steckenrider’s fastball characteristics not being great in a vacuum, it plays up because of how consistently he throws it to the top of the zone. That hints at the other part: he consistently pounds the top of the zone, which demonstrates his ability to locate his fastball where he wants. Where Steckenrider excels isn’t his fastball shape, as one might think. It’s how he locates it.

Now, despite all of this, you can likely surmise from Steckenrider’s 15.4 strikeout minus walk percentage that he doesn’t do much in the way of throwing strikes — at least in terms of called strikes and whiffs. And if you’re not convinced, consider that Steckenrider’s fastball CSW in the top shadow zone is 25.5 percent, placing him in the 40th percentile. That’s not encouraging, but what is is what happens when his fastball gets put into play.

Here’s an example from last season:

He throws his fastball above the zone here, where it plays the flattest; where it plays the best. Steckenrider throws three pitches, all of which play better than their shape because he’s able to locate them so well. And so, for Wander Franco, you’ve got to think that at his swing decision point, it’s unclear what this pitch is going to be. It, of course, ended up being a riding fastball above the zone, but in the back of his mind is Steckenrider’s changeup that could have come into the zone a touch slower, or, even more difficult, his curveball, which would have dropped to the bottom of the zone.

Now, Steckenrider doesn’t get a whiff, but he gets something better: a pop-up. Batted balls categorized as pop-ups produced a .017 batting average in 2021, meaning pop-ups are virtually automatic outs. This is where he excels. Steckenrider’s fastball is one of the best at generating pop-ups, and his curveball and changeup combo are one of the best at inducing ground balls. That means that, if you’re looking at his batted ball numbers in general, Steckenrider doesn’t look special, but at the pitch level, Steckenrider is either creating lots of pop-ups, or lots of ground balls. Those are the two most favorable batted balls for pitchers, and Steckenrider leverages all three of his pitches to his favor.

That raises the question: can this be sustained? Consider this pitch from Steckenrider’s first outing of 2022:

Steckenrider misses his spot, but he still manages to produce a pop-up. He’s a textbook example of a player making the most of the tools at their disposal, which makes for a precarious profile. Once the pop-ups go away, they’ll start turning into fly balls and line drives. Steckenrider doesn’t have the swing and miss stuff to counter such regression. He’s able to make it work because his fastball “rises” just enough, and because he’s able to put all three pitches where he wants. Any regression to either skill and he’s in trouble, but after seeing his first relief appearance, Steckenrider seems set for another productive season, even if it isn’t sexy.