a string goes "dead" and exactly what
a "dead" string is... is highly subjective, as players describe dead string as all sorts of things. Tension maintenance however, is one of the most straight forward measurements in all of tennis, and Luxilon 4G is the current champ. At a starting tension of 51 lbs., 4G ranks #1. SPPP ranks #47 best out of 239 polys tested. At the Wilson event I recently attended, all the frames were strung with 4G. The rep mentioned that it's just about the only practical choice for the new super open, string munching, 99s and 105s. He also hinted there will be a 14g version at some point. A bit too stiff for my arm, but I liked what I could do with the ball. Very control oriented, and spin friendly.