Polyester Strings Spin Tennis Balls

racquet stringer
Various kinds of materials can be used to string a tennis racquet.

As the U.S. Open kicks off in New York this week, the Williams sisters will go with natural fibers, but Rafael Nadal prefers a particular polymer. When it comes to stringing their tennis racquets, that is.

Steve Inskeep and David Greene report on NPR:

The game they’re playing is a game a [sic] skill, but the technology matters too. The game we’re seeing this week is in many ways different than it used to be, because the equipment has changed.

In the pro tennis world today, the material strings get more attention than the racquet. Nearly three decades ago, graphite racquet took over the game that wood had started. Strings have traditionally been made from animal intestines. Amateurs usually stick with inexpensive and forgiving nylon. Now, some high-level players are taking to polyester because tennis researchers say using these strings can help add more spin on the ball, which can be a critical advantage in a tennis match.

Roman Prokes strings tennis racquets for stars such as Pete Sampras and Andy Roddick. Prokes told NPR, “With the polyester strings, it kind of grabs the ball, you almost hold it on the strings, and it generates tremendous spin.”

Tennis researcher John Yandell, who is also editor and founder of TennisPlayer.net, is trying to get a better look at the theory. He used high-speed cameras to film Nadal hitting with polyester strings and told NPR:

No one ever saw another human being hit a tennis ball. That event lasts about four milliseconds, which is about 20 times too fast for your eye to register.

Tennis writer John Speckman told NPR that the footage shows that “the ball is more lively because the strings are more lively.” He added,” They’re moving basically twice as much. They’re sliding out of position and snapping back right where they came from before the ball leaves the strings.”

Will everyone switch to polyester? Not necessarily, because although players say that polyester strings deliver more power and spin, they can serve up a sore arm, too.

Source: “Polyester Strings Put More Spin On A Tennis Ball,” NPR.org, 8/30/11
Image by Suzanne Long, used under its Creative Commons license.

Rachel Petkewich is a freelance science writer and editor. She has worked as a research scientist in the chemical industry and spent eight years as a staff writer and editor at various science journals and magazines, including Chemical & Engineering News.