How can Aroldis Chapman throw harder than Jacob deGrom?


Last week, I met with a DPT (Doctor of Physical Therapy) who does contract work for a Major League baseball team. I was giving a presentation on the Physics of Baseball. During the event, the “Doctor” who specializes in the evaluation, treatment and prevention of sports-related injuries asked me the following question:

If Jacob deGrom (when healthy) can throw a 100 mph fastball, then how does Aroldis Chapman throw 105 mph - 5 mph faster? I said that I would think about it and send him my answer. Considering that the baseball throwing community could benefit from this answer, I decided to present my findings as follows:

Based on physics in connection with human biomechanics, I can with confidence say that Chapman throws harder for two reasons: (1) He releases the ball later in his delivery than does deGrom (2) He has more complete hip-rotation toward the target than does deGrom. So let’s take a look:

Jacob deGrom: Jacob deGrom Slow Motion Pitching Mechanics (Third Base Line View) - YouTube

Aroldis Chapman: Aroldis Chapman 105 mph pitcher - YouTube

(See the 38-second mark for a good view of his release point).

In closing, I’d like to mention my examination of Steve “Dalko” Dalkowski’s pitching mechanics, which revealed to me how he could have thrown his reported 110 mph fastball. I wrote about Dalko in this article: New Britain, CT: Home of the World's Fastest Fastball

Like Chapman, Dalkowski released the ball late into his delivery and with full hip-rotation toward the plate. He also threw with a bent-front-leg, which allowed him to lengthen his delivery to the plate. In physics, we call this Impulse (Force x time): I = Ft the time (t) over which a force (F) can be developed or maximized if you will. Another way to view the concept of Impulse (I) is to understand how it is connected to momentum (p). Perhaps you will recall from physics class that momentum (p) = mass x velocity: p = mv

Now let’s connect Impulse (I) to Momentum (p) by calling on Isaac Newton and his 2nd Law of Motion: F = ma = m(v2 - v1)/t

Where acceleration (a) is the change in velocity (v2 - v1) over time (t): a = (v2 - v1)/t

Starting from I = Ft = mat = m[(v2 - v1)/t]t = m(v2 - v1) = p2 - p1. The change in momentum.

This means that Impulse (I) = Change in Momentum (p) or I = (p2 - p1)

In pitching terms, this suggests that the longer a pitcher takes to maximize his force toward the plate the greater will be his momentum transferred to the ball: hence the fast in fastball. That’s what Dalko did: he had a large Impulse toward the plate by maximizing his force on the baseball thanks to a longer delivery and good hip-rotation.

Keep an Active Mind,

Prof. Don

Don R. Mueller, Ph.D.

(The Nutty Professor of Sports)

Jake’s fastest pitch is 102
Could he have thrown harder than that? Maybe.

Not anymore. But then pitching is much more than throwing hard. This guy threw upwards of 110 mph, but ended with an arm injury:

New Britain, CT: Home of the World's Fastest Fastball