“” Terence Hayes Jr - Driveline Baseball

Terence Hayes Jr

RHP, Bellevue College

Terence Hayes Jr. came to Driveline to rehab an arm injury with the hopes of earning an offer to play college baseball on the other side of the injury. He left the facility a year and a half later with what Driveline Director of Pitching Chris Langin deems a “Hand of God” slider and a roster spot at Bellevue College.

How did he manage that? It started with a discussion with Driveline Senior Pitching Coordinator Matthew Kress.

Kress, who would become Hayes’ trainer, explained to him everything he needed to know about Driveline’s return-to-throw program – about how the PULSE Workload Monitor is the single-most important tool he could use during his recovery, and how on the other side of his arm issues, he would be feeling better than he ever had before.

Hayes was in and got to work, becoming well-acquainted with Driveline’s PlyoCare Ball routine. What Kress soon realized was that Hayes was an extremely talented natural thrower of the baseball.

“What we quickly figured out was that Terence was on the younger side and was really looking to up his game so that he could get college offers,” Kress said. “So after that initial on-ramp and making sure the shoulder was back to normal, that’s when we really got into the nitty gritty.”

The nitty gritty involved putting some weight on Hayes’ frame – when he came into Driveline after his sophomore year of high school, he weighed 176 pounds and tested one standard deviation below Driveline’s high school average in overall strength.

In his latest High Performance assessment this March, Hayes weighed in at 204 pounds. His squat jump peak power had jumped from 3,464 Watts in October 2021 to 4,918 Watts in March 2023. His predicted velocity, in turn, had jumped from 80.5 mph to 85.5 mph.

In reality, Hayes was actually throwing 91 mph.

“Driveline talks about lowest hanging fruit,” Hayes said. “I was already pretty good at throwing, so it was about gaining muscle and the force I can put on the ball.”

Mission accomplished there.

“His strength has just skyrocketed,” Kress said of Hayes’ High Performance work.

That added strength has helped with more than just the fastball, too. The tick up in velocity that he worked so hard to get has paid dividends with his offspeed arsenal as well, which needed some work during his junior season.

Hayes was having success on the mound with his new 90 mph fastball, but felt like he was plateauing a little bit. He was having a hard time putting right-handed hitters away with two strikes.

The best thing he thought to do was consult with Kress.

“Halfway through his season, he was like, ‘Hey, can I come in? I faced this team last week and they kind of beat me up and I can’t figure out what the issue is,’” Kress recalled. “So I told him he was more than welcome, and what we figured out was that he was really struggling to put hitters away”

Hayes had been attacking those hitters with a fastball-curveball-changeup combo. He and Kress decided it was time to build a slider. They jumped in front of the Edgertronic camera and started testing different grips and different thoughts on how he wanted to throw the slider.

Progress was made. A lot of progress.



Spin Rate

Spin Direction

Vert. Break

Horz. Break


Slider 1

74.5 MPH

2405 RPM


1.7 in.

-9.2 in.


Slider 2

73.7 MPH

2493 RPM


5.5 in.

-13.3 in.



That 145 Stuff+ slider that Hayes and Kress developed is what Driveline Director of Pitching Chris Langin deems a “Hand of God” slider, one that only about 1% of MLB pitchers are able to throw.

Needless to say, Hayes started punching a lot of hitters out with the pitch.

“I’ve used it this year and last summer,” he said, “and it’s been really effective.”

It also helped him get an offer to pitch at Bellevue College, where he’s now in his freshman year. He’s come a long way from the skinny kid who came to Driveline to rehab a shoulder bug. He knows Kress and Driveline have a lot to do with that.

“It’s super helpful to have someone who knows what they’re talking about,” Hayes said, “and is going to give you good tips instead of me just guessing on what to do to get a pitch to move the way I want.”

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