There is not a single starting pitcher under 25 who is qualified for the ERA title this season. As much as baseball has advanced in the science of what makes a good pitch in a vacuum, this fact still stands as a testament to how difficult it is to become an established young starter capable of a full season in the big leagues.
Being healthy and having good pitches should theoretically yield to putting all the pieces together in a way that works. And that takes time, and that process is often interrupted by injury. So when you look at the ages of this trio of pitchers, you might find that they’re a little older than you expected. It’s just hard to be great right away.
These are their stories of the process of taking that raw clay and molding it into the vision of success they see before them.
A 24-year-old who pitched only sporadically before converting from a position game in his junior year at Nebraska, Schwellenbach is in the process of breaking out at just the right time for the Braves’ depleted rotation. That’s not the most common story, but it led to a unique fastball that is part of the righty’s foundation. Why is it unique?
“Having a low release,” he said last month. “The release point is not common. I played shortstop, I always threw the ball from down here.”
But there are plenty of pitchers who throw from lower angles. Schwellenbach needs to work on making sure his fastball doesn’t look like his typical arm slot.
“The more you go down there, the less vertical you’re going to get, the more flat you’re going to get,” he said of the four-seamer. “I tried to cut a backbone, so it’s not a tail. The more it tails, the less flat it will be.”
In this rendering by Max Bay, you can see that cutting the tail (and getting closer to zero horizontal movement) improves Schwellenbach’s fastball, making it less normal and therefore more deceptive. The heart of the ovals presented is the most “expected” movement of a given arm slot. Aaron Civale throws from a similar release point but his movement is much closer to expected. Schwellenbach, cutting his fastball slightly, stays outside the heart of the circle with his four-seam movement.
The job left to him to break out is to refine the cutter, curve and changeup he also throws. The difference between his fastball and cutter is just a tucked thumb, a subtle difference that still gives him 2-plus inches of drop and cut off the fastball. He recently changed his curved grip to a spike, which gave him a few ticks of sail and a few more inches of drop.
“The pitch was more of a swing-for-strike five weeks ago and now I can throw it for a strike but also finish it,” he said of the curve before modeling his grips for me.
Sorry for the terrible camera work, but you can still see how tonight’s Braves starter Spencer Schwellenbach changed his fastball grip to kill horizontal movement and make it weirder (and harder for hitters) in relation to his arm slot. A bonus is his curve grip change. pic.twitter.com/VmwqGFGO0b
— Eno Sarris (@enosarris) August 16, 2024
The curve has worked so well recently that he’s putting up four above-average Stuff+ pitches, paired with above-average command. That might be enough to make him an even better pitcher next year, but if he ever splits the splitter the same way he did with the curve this year, the sky’s the limit. Right now, he’s not practicing the changeup between starts and just seeing if he has it during the games.
“Whatever works that day, I just go with it,” he said.
And it all works pretty well.
First drafted in 2018, Mize has transformed while with Detroit.
“My delivery is a bit different but nothing crazy,” the 27-year-old said this month. “I had back surgery that changed some functional things. Now I’m more upright and vertical, and that came in the fastball.”
Fixing the back was huge because he had nerve pain in his left side, which for him is the “blocking” leg – the leg that comes down in front and provides the ground force reaction that helps convert a pitcher’s rotational energy into velocity, which is directed to. the plate Studies of the impact of the blocking leg into the ground have shown that it is highly predictive of speed. Mize got the surgery and found some ticks in his fastball as a result.
“After the surgery, I was in a position where I could get over my front side and carry the ball at the top of the zone,” he said. “It was based on position. I have less nerve pain, I couldn’t even put my front leg on the ground and go over my front side, but now I can do that a little better.”
Maybe you can see that here – a little higher stance with a release on the right, this year. Look at the corner of his shirt hitting his belt.
While he was right physically, Mize changed his arsenal. Most notably, he left the sinker behind in favor of a four-seam.
“Got away from the two-seamers to lefties because that got crushed in ’20 and ’21, so more four-seamers to those guys,” he said. “I’ve had a lot more success against lefties than righties this year, so it’s been a more complete arsenal for lefties.”
So why have Mize was good against lefties (.399 slugging) and struggled against same-handed hitters (.476 slugging)?
“A lot of this year has been the slider,” he admitted. “I can’t spin the ball very well, I’m just trying to spin the ball around 87, and lately it’s been slower. If I get 87-plus, the numbers are going to be great.”
Oddly, the numbers on Baseball Savant disagree, saying he gave up worse numbers on sliders over 87 mph than under 86. Maybe that’s because he loses 4 inches of drop when he throws it 87. As you can see from the interactive diagram below, adding speed only gets him to a redder (better) part of the diagram if he keeps the movement he has. According to Stuff+, he should either retain 85 mph speed and add more drop, or add speed and retain the drop.
That said, the pitch is good in theory even if it hasn’t yet led to the results he wants. A little tweaking could help him rediscover the promise of that top pick.
“It feels close to me. It was frustrating trying to find the right mix. I cleaned up the back end, really started to get over my front end, and my heater is over 95, I feel like everything is there,” Mize said. “I just have to constantly pull it out more. I didn’t think it would go this way, but that doesn’t change the fact that I know what I can be, and I will never settle for anything less than that.”
Staying healthy has been the biggest struggle for Hall, who came to the Baltimore Brewers in the Corbin Burnes trade. The 25-year-old left-hander has dealt with knee, back and elbow problems that have derailed him. But, as with Mize, getting those things right has allowed him to be fairer and may end up helping him in the long run.
“I’ve changed a lot mechanically because of my back and elbow injuries,” Hall said this week. “I was too rotational, now I’m more direct. When I had the low back problems last year, I couldn’t get any thoracic extension, and I pulled my shoulders forward and rotated, so I didn’t go into my back. I had to get it healthy. Stand tall, keep my shoulders back, and then I’ll get into the right positions.”
As he worked to heal the knee, it turned out that he also needed to heal his ankles. As a runner, I struggled with my ankles collapsing inward, or pronating, and Hall said that was a problem for him, too, until he found some exercises to help.
“I have the exact same thing in my ankle!” he exclaimed. “I do a lot of things to strengthen it. Trying to stretch the ankle – do a little toe yoga. It is huge. Sit down, have your leg at 90 and then move them like that.”
Of course there is a video, full of the usual soft yoga soundtrack.
After the toe yoga and knee and back and elbow rehab had their desired effect, Hall was freed up to think about the actual specifics of his pitches. He originally acquired an additional changeup when he first reached pro ball and discovered that his curveball grip did not work on a ball that had lower joints. But even that change improved over time.
“I changed my grip on that changeup for the first time,” he said of the pitch. “I always cast a two-stitch circle like that and then I changed it to a four-stitch. I found that my middle finger worked more than my ring finger, so with that old grip, that middle finger was too much off the ball, so I would start driving on it. Now with this grip it increases sideways. I threw it four years and it was really good, but now it’s more consistent.”
DL. Hall shows his changing grips before (left) and after (right). (Eno Sarris/ The Athletics)
With the new grip, he has the best drop and fade on the pitch he’s ever had, and the numbers agree that it’s been more consistent. In the meantime, he’s re-found his curveball, which he now throws 80-plus mph with more drop and cut than the average fastball. That looks like a real weapon. The last stop, like Mize, could be the slider who has shown inconsistent horizontal movement over the past few years.
“In ’21 I had an elbow injury, so I came back in ’22 switched to a sweeper, so I didn’t have to grind as much, I let the grip do it,” he said of the slider. “It made it a lot bigger and lefties could recognize it. I knew my target was a tighter, harder slider, but I was trying to find a happy medium. I went back to the bullet last year, but I was still using the sweeper a lot. It was way too slow, though. Lefties weren’t swinging at it and I couldn’t bury it on the back foot to righties. This year, I’m throwing the bullet, I just didn’t have the arm speed to get it right again.”
The good news is that the skater has been steadily regaining velocity throughout this season. The better news is that, as a lefty, he has the weapons he needs to take righties out without it. The best news is that he is fine in his back, elbow, knee and ankle. That makes him ready to redeem his pledge, help the Brewers in October and end up on sleeper lists again next season.
(Top photo by Spencer Schwellenbach: Alex Slitz/Getty Images)
