"And I never thought not to throw hard. Never. Even when I'd lost some control, and after two Tommy John surgeries, I still went out there and threw as hard as I could." Getty Images

Mark Wohlers remembers exactly when he became what Joel Zumaya is today.

A solid young set-up man on the Braves, Wohlers became THE hard thrower in the game, almost overnight. "I was in the pen with Leo Mazzone for a session, and I was infuriated. It was '95, and they were making (Brad) Clontz the closer, and I thought 'That should be me.' I hadn't pitched in like 17 days," says Wohlers, from his home in Atlanta. "I just remember throwing and Leo's face lit up, like, 'We haven't seen this before.' And I knew it, like, I was sure I was throwing harder, but didn't know what it was."

Wohlers routinely threw in the low 90's in the minors as a starter, and placed in a relief role with the powerful Braves, after a few years something clicked. "Go to the pen, you gain five or six on your velocity," he says—and he did. But that enraged pen session was a turning point. It taught him something: that throwing that hard was part in your head. "If you're physcally trying to throw it that hard, you can't. There's something more, a zone where it all comes together and it flows."

By age 25, as a still young, newly-minted closer for a powerful Braves dynasty, he heard the whispers about just how much velocity he'd gained. In those years, like his peak years of '95-97, he was routinely hitting 100 mph, and some said he'd hit 103 and 104 mph on occasions. Some said he was the hardest thrower ever. Some still do.

A fascination with velocity hasn't waned in the game.

"When I was coming up, the speed monitors weren't really a thing in stadiums," says Wohlers. "A few had 'em. When they did, I remember only looking a little. I looked in '96 at the All-Star game, because I heard the sound of the crowd when I threw it."

But by the time Wohlers went through what can only be described as a devastating physical and mental stretch, where a blend of elbow injuries and an almost total loss of control essentially ended his career in mid-flight, the stadium velocity signs were part of the game. Today, the radar gun readings loom over all pitchers in every park. Every time someone like Zumaya is on the mound, he knows 80,000 eyes look to the gun reading after each pitch as much as they do the right arm of the umpire. For some guys, it's an irresistible distraction.

"I don't want to say names, but you knew the guys who would watch," Wohlers says. "You know, after they threw the pitch, they'd do that little half turn, and they looked for the pitch speed. We could all see it."

The quest for speed came with a new problem for Wohlers: once you can hit 100 mph, 93 makes people wonder is something's wrong. Wohlers tried to learn from teammates Greg Maddux, Tom Glavine and John Smoltz, masters of their craft who could dial it up or back down at will, but partly because of the stigma that came with relieving—the one that said you had to throw hard—he never could adjust, even as a form of self-preservation.

"I was taught from high school all the way through the majors, you throw it as hard as you can as long as you can," said Wohlers. "And I never thought not to throw hard. Never. Even when I'd lost some control, and after two Tommy John surgeries, I still went out there and threw as hard as I could."

Discussing Maddux, who is years his senior and still pitching, Wholers says "I could never do what Greg did, and just decide to do it a different way. Most guys can't once you reach that point."

He laughs. "But that's why he is a first-ballot Hall of Famer still pitching, and I'm home with four kids."