Question of the Day: Serena's New Strings

TENNIS.com gear editor Justin diFeliciantonio and his technical advisers answer your equipment questions each day. Click here to send in a question of your own.

Watching the U.S. Open final last week, I heard a commentator mention that Serena Williams had changed her strings. Is this true? What was Williams using before? And what’s she using now? Any information on her set-up would be much appreciated.—Christina E.

It’s an interesting story, Christina. According to ESPN’s Kamakshi Tandon, Williams, who had strung with natural gut throughout her career, switched to a hybrid configuration this past spring. In particular, she’s using natural gut in the mains, and a new Luxilon monofilament called 4G in the crosses. As Tandon notes, Williams played her first tour match with the strings in Charleston, back in April. She won the tournament, and to date has lost only two matches since.

We’re all familiar with the power and resiliency of natural gut strings, and the extra spin that comes with monofilaments. But what’s the skinny on Luxilon 4G? Despite its name, the new co-polyester has nothing to do with telecommunications or bandwidth. Rather, 4G’s selling point, according to Wilson, is its tension maintenance.

“Most polyester strings lose tension very fast,” says John Lyons, Wilson’s Global Product Director for racquets and strings. (Wilson is the exclusive distributor of Luxilon products.) “And traditionally, the softer you try to make co-polys, the more quickly they lose tension. What 4G is built to do is play softer and still generate lots of spin, but also maintain its tension for longer periods of time. (Natural gut still holds tension better.) This means that players can do what everyone’s supposed to do with monofilaments: String at lower tensions. Many players don’t want to string in the high 40s to low 50s [lbs.], because they know that the tension will drop off. We think 4G is going to help change that.”

While it’s hard to objectively determine whether Serena’s new strings have upped her RPMs, one thing’s for certain: They haven’t hurt. For all those who watched the women’s final this past Sunday: Remember that deuce point in the second game, when Williams, running deep in the court to her left, flipped a backhand lob over Azarenka’s head? (It's at 1:33 of the video below.) As Vika stood on the service line and watched helplessly as the ball arced smack on the baseline, I remember thinking to myself, “That’s a Luxilon shot.”