I had the great pleasure of speaking with "THE" pioneer in tennis physics, Professor Howard Brody. I love hearing Professor Brody's stories and I always learn a great deal from him.
Among his many accomplishments he has written almost 100 technical papers on tennis,
appeared on television many times from the children's science show,
"Newton's Apple" and Australia's "Beyond 2000" to the physics
of football for the National Football
League. He is featured on an instructional video with Vic Braden called
"Science and Myths of Tennis" and was even interviewed by Time
magazine regarding his work in tennis racquet science. Prof. Brody is a member of the Sports Science
Committee of the USTA, a member of the International Tennis Federation's
Technical Committee and the science advisor for the Professional
He was given the
Tennis Educational Merit Award from the International
Tennis Hall of Fame (named into the International
Tennis Hall of Fame as an educator).
He has been a tennis player
for almost 60 years.
If you have not seen it already his new book
The Physics and Technology of Tennis is a classic and will answer just about all your questions on balls, string and racquet science and technology.
I asked Prof. Brody how he became involved in tennis physics. In particular I wanted him to share his early interests with our young readers.
Brody: "Even as a young boy growing up in Newark, New Jersey, I loved building
things. I had erector sets, Lincoln Logs and chemistry sets. I really
enjoyed electric trains and learned a lot about electricity that way. I
think you learn all the basics of electricity by hooking electric trains
up and making everything work together. It was interesting the way I became involved in physics and then tennis
science. I couldn't
have been more than 10 or 12 years old at the time. My uncle came back
from the war and he had small "pocketbooks" that he gave to me. One of
them was called "Atoms in Action" by George Russell Harrison. And I was
just fascinated with this book and that was when I first thought that I
wanted to become a physicist when I grew up."
Later Brody attended the Massachusetts Institute of Technology (MIT)
and earned an SB in physics in 1954 and a Ph.D. from the California
Institute of Technology (Cal Tech) in High Energy Physics in 1959. He has
been on the faculty of the University of Pennsylvania since 1959, but "retired" in 2000. (I think he has been more active since he has allegedly "retired.")
The story has another unique twist to it though.
Brody: "When I later attended
MIT, the dean of science was named George Russell Harrison and he ran one
of the science labs. I was really excited when I realized it was the
same person and told him the story about reading his book when I was a boy
and how it had inspired me to become a physicist. I think it made him
feel very good to know that his book had encouraged someone to become a
I asked Professor Brody about the late Howard Head - what he was like
and how was the oversized racquet developed?
Brody: "Howard Head was an engineer. He went to work for the Martin Company in Baltimore designing airplanes and parts, etc.
While he was there he decided to go skiing one day. He didn't know how to ski so he took some lessons. He was not very good at this skiing business. But he decided it wasn't him - it was the skis that weren't so good. So he decided he was going to use modern aircraft technology to make a metal ski which would be better than the skis they had at the time. He started working on that problem and eventually quit his job with Martin.
He kept himself alive financially by playing poker - he was a card player. He was making these honeycomb material skis, baking them in his oven.
Eventually he was successful in making this ski. He then formed the Head Company which was so successful that in a couple of years he was making the majority of skis in this country - these metal honeycombed skis.
He eventually sold the company out but by then they were also into tennis and they made the Arthur Ashe racquet which was an aluminum honeycomb racquet. He sold the company and retired. He built a tennis court in his backyard, took lessons and got a ball machine and discovered that he wasn't a very good tennis player. True to form he decided that it wasn't Howard Head, it was the tennis racquet. Also the ball machine wasn't very good. So he redesigned the ball machine and bought the company that made the ball machine and began making a much better product.
One day Head walks into the company and says that he had a new tennis racquet. Being that he was essentially the owner of the company, they gambled and made 40,000 of them which sold. That was the Prince racquet, that aluminum green throated thing which was not a particularly good racquet but it was better than many other racquets.
The company then made the Prince graphite which was a very good racquet and the rest is history. They acquired a patent. Howard Head got a very good patent that essentially covered all racquets with a certain head size like 90 to 125 square inches (approximately) and he was collecting royalties from everyone who made an oversized racquet."
I asked Brody, "How did you get involved with Howard Head?"
Brody: "One day I was taking my family on a vacation down in Florida and we're at the tennis courts and I notice someone with an oversized racquet. So I asked the local pro there what he knew about them and why it was better. He had
He was a very good pro. He could teach marvelously. I watched people take lessons from him, he was really very good, but he didn't have the vaguest idea about the science of the racquet.
So there I am, I'm a physicist; I've been a physicist since my late teens and I had started playing tennis in my early teens. I put them together and I wrote an article. I went into my lab and I did some simple tests and learned some things about racquets.
The first thing I saw was a patent number on the racquet. So I wrote to the US patent office and I bought a copy of the patent and I learned some things. It listed the owner of the patent as Howard Head and the Prince Company. I wrote to Howard Head telling him what I was doing and I published an article in the American Journal of Physics. Well, the New York Times Tuesday science edition picked up the article and for a couple of months I became a media event - Voice of America, Action news. Everybody descended on me because here's a serious physicist and he's investigating tennis racquets.
I discovered things about sweet spots.
It was great fun and that was one of the reasons I decided to give up particle physics and go into tennis racquet physics. People were so much more interested in it.
So I wrote to Howard Head, he wrote back, he sent me some racquets and at a later time they needed some help because they were trying to defend the patent. Who better to serve as an expert witness than the only person in the country who's ever written a technical article on tennis racquets. So I helped them defend the patent, which I've done a number of times since then."
Why was Head's racquet better?
Brody: "First place it's wider which means its moment of inertia is greater. The moment of inertia is that quantity which resists twisting. The racquet therefore is more stable. If you hit a ball off-axis it won't twist the racquet as much and you don't lose as much power. The second reason that the racquet was good, up to then the sweet spots of the racquet had always been down near the throat of the racquet. People had tried all kinds of ways to move the sweet spot up to the center of the head. Howard Head did just the opposite, he kept the sweet spot where it was but he enlarged the head, so the center of the head of the racquet came out where the sweet spots were. Ingenious! And that was enough to grant a patent on that idea."
What are some of the projects that you most enjoyed working on?
Brody: "In some ways the patent litigation was great, because I had to go back and read the literature from the 1800's on to see if anyone had ideas comparable to Howard Head. There were people who had oversized racquets but none of them had the same idea he had and there were people who had huge racquets. Racquets with big heads, small heads, all kinds of things. Seeing the logic behind them and what the problems were was just very, very interesting. So that was a project I enjoyed a great deal.
I enjoyed the work I did on a racquet's sweet spot. I looked at the vibration sweet spot and how it changed as you gripped the racquet. When I started into this I wasn't sure whether a handheld racquet acted as if it were a free racquet or a vice held racquet or some combination.
And that's one of the early things I did, I determined on the basis of vibrational patterns that a handheld racquet essentially behaves as if were completely free.
The other thing that I determined, which the literature at the time was sort of fussy on, was that looser strings give you a little more power, a slightly higher ball velocity and I came up with the reason for that. If you read the older tennis journals they used to say, tight strings give you more power and the reason for that is that the top players have tighter strings and they have plenty of power and that's completely backwards."
I asked Prof. Brody to tell us about his new book,
The Physics and Technology of Tennis and the collaboration with co-authors
Prof. Rod Cross
Crawford Lindsey of the US Racquet Stringers Association.
Brody: "I've been in the tennis business for 15-20 years and I've
been involved in science videos. There was an Australian video team that
I worked with for the Australian science program called "Beyond 2000" and we shot three episodes.
Prof. Rod Cross in Australia, a plasma physicist, was watching television and there I am, explaining the physics of the tennis racquet. Rod decides that's what he wants to do, because he's a physicist and he's played tennis all his life as well. He emailed me and we started emailing back and forth and we emailed back and forth with each other for about 5 years before we first met. We first met at the ITF Tennis Science and Technology Conference in London in 2000. Crawford Lindsey was there too, representing the United States Racquet Stringers Association.
By then I had written a fair amount of papers and a semi-popular book called
Tennis Science For Tennis Players and Rod had started writing papers too. About a year later I get an email from Rod and Crawford saying that they were planning a big book on the science and technology of tennis, would I be interested in being a co-author. It looked like a great idea to write "THE" reference manual or "THE" encyclopedia of technical tennis, so I agreed to it. With Crawford shepherding us through, Rod, Crawford and I wrote our parts. Crawford put the book together which has virtually everything known to mankind about the technical and physics aspects of tennis.
The book has about 450 pages, 45 chapters. There is a small amount of redundancy because Rod looks at things in his way and some things I look at my way. The book weights about 2 pounds and 1000 copies have been sold so far. So when anyone ever asks how sales are going I tell them, we've sold a ton of them."
What new information did you learn in writing the book?
Brody: "In my case it was mostly work I had done over the years; in Rod's case there's some new material that he had never previously published. Since he's fairly new in the business he was learning and as he learned he put things into the book. So I think you'll find a lot of the material in chapters Rod wrote are available nowhere else. Some of the material I wrote has been previously published. Crawford of course is a technical editor and publisher of Racquet Tech and he also made his contribution.
In what area in tennis science do we lack knowledge?
Brody: "There is one gaping hole in our knowledge and that's the swing speed versus racquet mass/racquet moment of inertia. If you go to a heavier racquet does that slow your swing down enough to make you lose power? No one knows this. If I add a couple of ounces to the tip of a racquet and then serve, do I get higher ball speed or lower ball speed? No one knows this.
So if we could measure the racquet head speed as a function of either the swing weight or the mass of the racquet then we could figure out whether a heavier racquet or a lighter racquet was optimum for a player as far as ball speed was concerned. There has been an attempt to do this with about 8 people; but that's not enough and that amount of data isn't good enough. So what's needed is a study with hundreds of people. That's a major area that needs investigation."
What's the most common question you are asked?
Brody: "What tension should I string my racquet! That's clearly the most common question and there's no real answer for that. All the manufacturers make very good racquets and each one is different in a slightly different way. I can't even recommend a racquet length or a racquet weight, because it depends so much on an individual's physiology, style of play, what they want to do in tennis, etc. So there's no way I can give advice on that.
I can for example tell you that if you want a little more power and you are stringing your racquet very tightly you might reduce your tension a little, things of that sort. But a general statement on which is the best racquet - I can't say that."
What information from tennis science, physics or technology would help most players.
Brody: "Your choice of a racquet depends in many ways on the style of play and how good you are. If you are going to play a recreational game, standing at the baseline, just returning shots then you clearly want a racquet with a big head - an oversized racquet. If you're playing an aggressive serve and volley game then that big oversized racquet head may not be exactly what you want. You may want a slightly smaller head, a slightly lighter racquet. So the important thing is to match the characteristics of the racquet to your playing style. The wider headed racquet gives you more stability, but also at the same time it's a little bit less maneuverable. So if you are playing serve and volley it isn't exactly what you want. The oversized head does not enhance your serve particularly; it probably does enhance your ground strokes."
I really appreciated Howard taking the time to talk with us. I'd like to mention that the
2nd ITF International Congress on Tennis Science and Technology will be July 28 - 30 in London and the "Best Paper" Award for the conference has been named the Howard Brody Award.
Hope You Have Enjoyed The French Open .. Until next month ... Jani