If there's a model for the era of lower-tension tennis, it's Roger Federer. The meticulous Swiss comes to the court armed with nine rackets strung at three different tensions ranging from 48 to 52 pounds in the vertical main strings (and 3.3 pounds lower for his cross strings)—numbers he picks with his stringer the night before. If it's hot out and he's playing a monster hitter, he'll bring more rackets on the tighter side.
Federer almost never restrings a racket during a match. He usually burns through seven or eight sticks during a five-setter, often switching from tension to tension, and generally going tighter as the match progresses, says his stringer Nate Ferguson, owner of Priority One, the company many top pros hire to handle their stringing.
In 2004, Federer was stringing his rackets at 55 pounds, which was considered ultra-loose for that time. While stringers say he already has the lowest tension of any of the men in the top 10, stringers say he's gone down even more.
Ferguson of Priority One said Federer uses vertical main strings, made of gut, strung at 49 pounds and a synthetic brand called Luxilon Alu Rough in the cross strings at only 46.2 pounds.
