What Determines How Hard Someone Can Throw?

| 1 Comment

As a kid, I always knew what I wanted to be when I grew up. Now, even though I don't like to admit it, I realize there's no chance of it actually happening. That's because my childhood dream was to become a professional baseball player and play for the New York Yankees. However, my ambitions didn't end there. As a diehard baseball fan and hopeful future pitcher, I wanted to be one of those Major League fireballers who could blow 100 mile per hour fastballs right by the opposing batter for the strikeout. Unfortunately, I'm 5'10" 150 lbs, and a completely mediocre athlete. However, I've always been curious as to why some people can throw harder than others. In professional baseball, pitchers' fastballs range in speed from the upper 80's to over 100 miles per hour, but the average in 2013 was  

Does a pitcher's max velocity depend on their physical size, strength, technique, or something entirely different?

Adrian Bejan, a professor of mechanical engineering at Duke University, believes that "for pitchers...height means speed". To explain why, Bejan utilizes a well known scientific theory that he personally developed known as "constructal law"


This theory states that a "larger and taller machine...is capable of hurling a large mass farther and faster" than a shorter, smaller machine." In other words, on average, larger and taller pitchers tend to throw faster than smaller shorter pitchers. When larger pitchers fall forward towards home plate when delivering a pitch, they are able to utilize their greater masses to generate more force behind the ball. That is why, according to Bejan, pitchers tend to be the tallest players on the field. After compiling years and years worth of statistics with the help of his students, Bejan found "The average height of the pitchers active at least one season has increased almost at a constant rate during the past century from five foot, nine inches to current levels" and that "Shortstops and second basemen, who have the shortest throws to first base, tend to be the shortest players on the field."

Bejan's theory makes sense when you look at current pitchers like Aroldis Chapman of the Cincinatti Reds. He is 6' 4", 205 pounds, and has the fastest pitch on record in an MLB game (106 mph). The theory also checks out when looking at baseball legend Randy Johnson who was 6' 10". weighed around 225 pounds, and consistently threw in the upper 90's. However, if physical size plays that big a role in a pitchers' max velocity, what explains guys like Billy Wagner who could top 100 mph on a radar gun while only being 5' 10" tall and weighing 180 pounds?

George Washington University professor Dr. Neil Roach argues that physical size and muscle strength are not nearly as important to a pitchers' velocity as is technique. In a recent report in the science journal Nature, Roach detailed an experiment he did as a graduate student at Harvard in which "used motion-capture video to analyze the throwing motion of 20 college athletes, who hurled baseballs at a target about 100 feet away, with and without a brace that restricted shoulder motion". 


Then he and his team "analyzed the structure of the shoulder and upper arm, the motion and the forces involved, and concluded, first, that muscles alone cannot account for how hard and fast humans throw". After measuring the amounts of torque generated by the rotation of the players' humeral bones during the cocking phase of their different throwing motions, it was found that pitchers that generated more humeral torsion threw at higher velocities than those who didn't. In addition, when the rotation of the players' humeri was restricted by a brace, they're pitch velocity declined significantly.

So what does that all mean? According to Roach, a player can gain significant velocity on their fastball by solely changing their mechanics. With the help of coaches, pitchers can learn how to speed up their shoulder (and humeral) rotation, generating more torque and therefore more miles per hour on their pitches.

In my opinion, Adrian Bejan and Dr. Roach are both correct because it seems to me that physical size and pitching motion are both significant factors in determining how fast someone can throw. However, I put a lot more faith in Dr. Roach's findings. Bejan merely had a theory and did an observational study of historical data while Dr. Roach conducted a well-designed experiment. I acknowledge that the sample size of 20 college athletes is small, but the other aspects of the study were carried out well. For example, in selecting the 20 participants, Dr. Roach controlled throwing ability by requiring all potential subjects to pass a "performance task" before being selected. In screening the participants, Roach also collected data on height, joint segment lengths, circumferences, and controlled those variables accordingly. Lastly, his experimental report is thorough and details how all the measurements involved were carried out making the study able to be reproduced with greater ease.   

In conclusion, I don't know if researchers involved in sports science will ever truly know what factor is most significant in giving a baseball player the ability to throw fast, but now I'm definitely interested to read more on the topic.

What do you think gives certain people the ability to throw so much harder than others?


1 Comment

This was a really interesting read, I really liked the blend of sports and scientific processes. The first theory seems to be a bit flawed to me, especially because you stated it was only an observational study and therefore couldn't technically prove anything. I have thought about this topic before too, and after reading the 1st theory I was questioning how true it was. I remember in middle school I went to my school's carnival with a buddy of mine. They had a speed pitch booth which measured how fast you could throw a baseball. My friend and I tried it out, and I threw 50 mph while my friend threw 63 mph. At the time, I was around 5'4 and by no means a big kid, but my friend was no taller than 4'11 and probably weighed under 100 pounds. I was curious to see how Mr. Bejan would explain that, until I saw the second experiment. I now understand that my friend most likely just had much better mechanics than I did; He pitched for a rec league team, and I quit baseball in 3rd grade. Based on this experience, and the information you compared in your blog, I would say I also agree with Roach's conclusion. The question I have for you is this: If Aroldis Chapman has the fastest pitch in a game on record, does that mean that his mechanics are the best in the game? Or is there some other 3rd variable that hasn't been identified yet?

Leave a comment

Subscribe to receive notifications of follow up comments via email.
We are processing your request. If you don't see any confirmation within 30 seconds, please reload your page.

Search This Blog

Full Text  Tag

Recent Entries

My name is __ and I am an Addict
No matter how old I get I cannot stop the habit of biting my fingernails. I have tried everything…
Why are girls with fathers less likely to be promiscuous?
There are many studies that support the fact that girls without fathers are more likely to be promiscuous. In…
What's in the Water?
It seems like everywhere I go, the tap water tastes different than at my house. I always wondered what sorts…

Old Contributions