GAMMA Guts: How Dr. Harry Ferrari’s Tennis Strings Changed the Game

June 28, 2017

GAMMA Sports blog about how Dr. Harry Ferrari revolutionized tennis string.

Question: What do you get when you combine a tennis match, broken natural gut strings, and a nuclear engineer?

Answer: A revolution.

One weekend in the 1970s, GAMMA founder Harry Ferrari was playing tennis with some friends. It was how he preferred to relax and stay active when he wasn’t working as a nuclear engineer at Westinghouse. By day, Dr. Ferrari was a brilliant scientist: he contributed to innovative advancements in nuclear equipment and fuel materials, had articles published in multiple scientific journals, and was a sought-after speaker and lecturer.

But that weekend, there was a hitch in the game: Dr. Ferrari’s natural gut tennis strings snapped during play. Rather than forfeit, he borrowed a racquet from a friend on the court—a Jack Kramer wooden racquet, identical to the one he preferred for play.  It had the same grip size, the same weight. The only difference? It was strung with synthetic strings. The best available at the time, in fact.

Most avid tennis players today know that there’s a serious difference in playability between natural and synthetic gut tennis strings. On that weekend, Dr. Ferrari was reminded of these differences the hard way: Once he started playing with that borrowed racquet and its synthetic strings, it changed his game, and not for the better. He’d been winning the match with his trusty natural gut strings, but the switch to synthetic made him blow it.

In the 1970s, though, synthetic strings were still relatively new technology. Natural gut, made from the intestines of sheep or cows, had been the favorite material for about a century, but it was expensive to make. Not only that, it was susceptible to moisture damage: Tennis players in humid climates found that their strings broke more frequently.

Sure, the new synthetic technology was durable and affordable, but it lacked the playability of tried and true natural gut. It was stiff and lacked control. If these were supposed to be the best synthetic string had to offer, clearly there was room for improvement.

Those strings were bad, Dr. Ferrari thought after the match. So bad, in fact, that they sparked an idea that only a nuclear engineer could have. Using his knowledge of nuclear engineering processes, Dr. Ferrari started to do experiments on tennis strings.

Synthetic strings were nylon-based materials, he reasoned. If he were to irradiate them with gamma rays, then perhaps it would change the cross-linkage of the various molecules to make the string more resilient. So, he bought several sets of synthetic gut strings and subjected them to different levels of radiation.

Then, he took to his garage, where he set up a facility to test the strings. He hung the strings—all of which had received different levels of radiation exposure—and attached a 50lb weight to them. He plucked each string and carefully noted the vibration of each.

It was a matter of physics: The longer the vibration, the less energy taken up by the string, and the more energy available to pass to the ball. In his experiments, he noticed that the higher the level of radiation, the longer the vibration lasted.

The end result was a pliable string that offered the sturdiness of synthetic materials and playability that rivaled natural gut. Dr. Ferrari’s irradiated strings had the kind of power, feel and control unparalleled by any other synthetic string at the time.

With that, GAMMA Gut was born.

His revolutionary strings created the caliber of performance strings most tennis players are familiar with today. In 1977, the United States Racquet Stringer’s Association rated GAMMA Gut the #1 string for the first time—and continued to do so for the next 23 years!

Today, Dr. Ferrari’s legacy lives on. Here at GAMMA, we still strive to embody our founder’s spirit, dedicating ourselves to his desire to never settle. We’re determined to help athletes grow, perform and ultimately become the very best they can be.