How Orioles pitching prospect DL Hall used a chain-link fence and motion capture to become ‘the new DL’

Jon Meoli, Baltimore Sun
·8 min read

DL Hall, the Orioles’ top pick in the 2017 draft and one of the top left-handed pitching prospects in all of baseball, was finally getting his 2019 season back on track at High-A Frederick when an oblique injury ended his season a month early.

The wait to get back on the mound in real games proved to be much longer than he could have ever imagined as the coronavirus pandemic wiped out the 2020 minor league season and cost prospects like Hall valuable development time. He would have likely spent all of 2020 at Double-A Bowie, putting the 22-year-old left-hander on the cusp of the big leagues at Triple-A Norfolk this year.

Instead, he had a whirlwind year of development he believes changed his life, from throwing into a chain-link fence at home in Valdosta, Georgia, to developing at the team’s alternate training site and the high-tech Wake Forest Pitching Lab, and capping it off with a data-driven facility experience at the same venue that helped reinvent Orioles starter Matt Harvey.

“It’s a really great feeling to come in knowing that I’ve had a whole year of work, and it also makes you excited to show it off because the fans of Baltimore and people like that haven’t gotten to see basically the new DL,” Hall said. “That’s always exciting to think about. I’m just ready to get out there on the field and show it.”

Change of plans

The old DL, to the extent that a teenager can be considered such, was plenty talented. The athletic left-hander ran his fastball up into the mid-90s and had a four-pitch mix with potential that needed refinement. He came into pro ball with what was considered the best curveball in his draft class, but couldn’t find a feel for it in his first full season in 2018 at Low-A Delmarva and mostly threw his slider, though they weren’t necessarily distinguishable. His changeup also had plus potential.

But throwing strikes was a problem for Hall, who has walked 5.1 batters per nine innings in his professional career. So in a year of consequence-free development, the priorities were clear.

Hall worked out in his hometown and threw at Valdosta State ahead of 2020 spring training. He came in feeling as if he’d ironed out some of his command issues, but never really got a chance to show it before he and the rest of the Orioles minor leaguers were sent home to wait out the pandemic.

“When we got sent home, it was really hard,” he said. “Everybody was still at school for a little while before they got sent home. Some days, I wouldn’t have people to throw with or the college wouldn’t be practicing that day or something. I’d have to go to the local park and throw into the fence. Luckily, I had about 30 balls so I only had to pick them up after about 30 throws.”

That period, however, proved important for Hall in terms of his breaking ball development. He was charged with separating the two, and pitching coach Justin Ramsey said Hall’s work on that front was apparent as the summer progressed.

“For me, it was like a wrist positioning thing,” Hall said. “I focused on my wrist position and getting more on top of my curveball and not letting it get to the side of it like more of a slider, and just getting that true shape of a 12-6, just working on the shapes and seeing them and getting a little more sweep on my slider.”

When baseball resumed and Hall came to the Orioles’ alternate site at Bowie, he was one of the youngest pitchers there. He looked around upon his arrival, surrounded by big leaguers and older prospects who would soon make their major league debuts, and told himself he belonged.

The two-plus months there went in waves. Early on, before hitters adjusted to him, his stuff won out. Once they saw him a few times, they figured him out and he had to adjust. Hall had plenty there to help his growth. Ramsey said Hall spent time with All-Star left-hander John Means during Means’ brief time at the camp to learn from him. As the camp went on, they clarified Hall’s attack plan against righties and lefties.

“With that simplified approach, just could truly just focus on the feel of those pitches and really start filling up the zone with those,” Ramsey said. “Now, I don’t want to get too far ahead, but as we go forward, he has the feel and ability to throw all four of those pitches any time he wants.”

Machine learning

The key for any pitcher with that kind of arsenal, though, is keeping pitches in the strike zone. Hall started to realize that year in Frederick that when he’s in the strike zone, he’s hard to hit. The Orioles staff did plenty of work keeping his delivery consistent at the Bowie site, and his last outing there sent him off on a high note.

Hall had just gone home to see his grandfather before his passing and returned for one final outing, his best of the camp, in which he threw a fastball 100 mph for the first time. What came next was another unique effort to lock in his delivery and allow him to hit those heights consistently.

Hall and a few other Orioles pitchers, including left-hander Zac Lowther, went directly to the Wake Forest Pitching Lab for state-of-the-art biomechanics work. They were outfitted in full body suits with motion-capture sensors that made them feel like they were being scanned for a “Madden” video game and captured every detail of their deliveries.

“We threw a bullpen and got to look at some mechanical stuff that’s kind of hard to see with the regular eye,” Hall said. “With me personally, it helped me out with some timing things and figuring out some hand-breaking with my leg, things like that, just some timing issues that it helped show it a little bit easier.”

One rival scout who had seen Hall each of the past few years said the difference that came from that experience, illustrated at the team’s fall instructional camp, was “night and day,” though Hall believes it was more of a progression.

“I wouldn’t say all from Wake Forest,” he said, “but more so being able to work along with the older guys and pitching coaches at alternate site and just kind of finding my rhythm, I felt like it was a true showing of work that I put in towards getting my command better which comes from fixing those things like timing and all that.”

Said Ramsey: “He kind of cleaned up his rhythm, tempo, timing and direction with his delivery. That’s when it really started to click.”

The offseason proved to be productive as well. Hall got a house in South Jersey and trained at A2i Fit, and threw at the Baseball Performance Center, where Harvey was introduced to some of the pitch data that has helped his revival with the Orioles.

While Hall admits to being the type of pitcher who doesn’t want to be thinking on the mound, the value of a data-driven facility was clear given his shutdown goals of differentiating his breaking balls. Seeing the spin axis and movement on every pitch confirmed he was on the right track.

‘This could potentially change my life’

Being away from home for the winter was a small sacrifice he hopes will bring about significant gains.

“I was like, ‘I’m away from home, away from family and friends. But this could potentially change my life or my career,’” Hall said.

All that has delivered a reinvented pitcher to minor league spring training and, eventually, Bowie. His fastball in spring training is consistently in the upper-90s, with triple-digits again in reach. Catcher Adley Rutschman, the Orioles’ top prospect and a hopeful future battery mate in the big leagues, said Hall is a “stud pitcher,” one who has “a lot of potential and a lot of upside.”

Bowie manager Buck Britton said the changes in Hall have been apparent since they were together at Delmarva in 2018. He could only describe Hall’s spring training as “dominant,” with better command and four pitches that can play in the big leagues.

“The stuff is ticking up a little bit as he goes, but the biggest thing is the repeatability of the delivery is allowing him to throw more strikes,” Ramsey said.

“It’s been fun,” Ramsey said. “Simply put, it’s been fun. To see all the hard work and dedication that he’s put in, coming through and almost speeding up the process of what it is. I don’t know the timeline, 2021 or 2025. I just know he’s definitely doing things that are going to allow him the opportunity to be where he wants to be — and where we all want him to be.”