UTK Vacation Post 2
Revisiting Dr. Mike Marshall
In 2004, Saving The Pitcher* leaned heavily on the work of two men who sat on opposite ends of the baseball orthodoxy: Dr. Tom House and Dr. Mike Marshall. One was a coach of superstars. The other built an empire of ideas on the margins. In the two decades since, House’s work has become more mainstream, filtered through private labs and high-speed cameras. He’s got a great app, Mustard, where he regularly does Q&As and plenty of videos. Marshall’s has faded, his theories archived on aging web pages and grainy VHS.
His daughter, Deborah Marshall, has lovingly archived much of his work at DrMikeMarshall.org. After his death, a treasure trove of research might have been lost (and for a time, was), but it’s all here again and we all owe a tip of the cap to her for that. But in a year when arms are dropping like flies — again — it’s time we talk about what Marshall saw that the rest of us didn’t.
The place to start is the concept of forearm bounce. Not to be confused with layback, which is a common mistake and a costly one. Layback is what happens when the shoulder externally rotates, and the forearm “lays back” behind the head during the pitching motion’s cocking phase. That extreme rotation acts like a stretched rubber band, storing elastic energy before release. It’s visible, it’s measurable, and it’s part of how guys throw 100.
Marshall didn’t like it, but he wasn’t arguing with the layback itself. His problem was with what happened next: the uncontrolled rebound that followed.
He called it forearm bounce and wouldn’t change, even a little. I have notes from a conversation around Saving The Pitcher where I tried to make it a little more marketing savvy and he had absolutely none of it. Forearm bounce it was and would ever be. The violent, whipping snap of the forearm back into position before the ball is released. In his view, this bounce wasn’t just a side effect. It was the root cause of arm injuries. The UCL, the fragile band that anchors the inside of the elbow, absorbs the brunt of that snap. The harder the bounce, the more stress that rope takes. Eventually, it frays.
In response, Marshall built a delivery that tried to remove it entirely. No bounce. No layback. No supination. He kept the elbow high, rotated the arm early, and forced pronation well before release. His pitchers looked like javelin throwers with nowhere to go, but they were healthy. (Remember, a javelin thrower was the second surgery Dr. Jobe did, between Tommy John and Brent Strom. I still believe I found him.) At least the few who made it through the program. There’s issues and while Marshall said his delivery removed this, the video - what we have - often showed some elements of it, because it’s simply so natural. Worse, his disciples have become cultish and done exactly what Marshall hated most - they altered his methods.
He didn’t tinker with mechanics. He nuked them from orbit and started over. Which, for most of baseball, made his ideas unusable. You can’t retrofit an age-20 prospect’s delivery without breaking something else. You can’t tell a high schooler to throw like no one they’ve ever seen.
That doesn’t mean Marshall was wrong.
We’re now in an era where pitchers are throwing harder, younger, and breaking faster. The IL is crowded with elbows. Velocity is up. Injuries are up. We’ve optimized every measurable element of performance and we’ve tested the physical limit of what the arm can tolerate as currently trained.
So here’s the question: what if Marshall had the diagnosis right, but not the cure?
You won’t find anyone throwing exactly like Marshall’s blueprints today, but you will find echoes. You’ll hear pitching coaches talk about early pronation, about managing deceleration loads, about forearm strength and shoulder stability. You’ll see movement specialists train the posterior chain and avoid torque-inducing drills. You’ll find motion-capture labs analyzing elbow valgus and trying to soften the extremes of layback.
The difference is, they’re trying to mitigate forearm bounce. Marshall wanted to eliminate it. That’s the fundamental shift. Baseball accepted that layback was necessary, that it was the cost of velocity. Marshall said no. Build velocity without bounce. Sacrifice style. Sacrifice convention. Save the arm. Maybe now, after decades of denial and four billion dollars in losses, we’re finally ready to hear that again. Or maybe not.
Marshall’s ideas were never going to be adopted wholesale. He didn’t allow for nuance. He didn’t compromise. His pitchers had to throw his way or not at all. That rigidity was often his undoing. In that rigidity, there was clarity. When I wrote about it in Saving The Pitcher, he accused me of dumbing it down, of “writing his method for third graders.” Which was, in fact, what I was trying to do, or at least for their coaches and parents.
Layback is part of the throwing motion. Forearm bounce is the price we pay for letting it go too far. Marshall saw the bill coming. Everyone else just kept charging velocity to their tab. More accurately, their pitchers’ arms became the credit card.
The current generation of players doesn’t need to throw like Marshall’s disciples, but they do need to learn what he was trying to prevent. If nothing else, his work reminds us that not all velocity is free. Some comes with interest and a scar.
He may have lost the argument, but he wasn’t yelling about nothing. Maybe that snap, the one we slow down and admire in every highlight, is exactly the one we should fear the most.
*I don’t put in an Amazon link because while I’m still proud of that book, it’s simply out of date. The things I say in there are about four generations back on learnings and I don’t think anyone today should read it.