jayl0ve wrote:I think Sampras used 19 or 20 gauge strings...super thin strings!
Nope, that was a myth. He used 17 gauge and 17L - 1.22mm on grass, 1.25 on other surfaces. The 17L was either squash gut, or custom made; I'm not sure, but I think it was squash gut. I tried some 19 gauge gut once, and you couldn't even put 55lbs of tension on it.
I used to use 17 gauge gut mains, with 18 gauge Timo crosses. That was a very sweet feeling hybrid.
As far as the spin, everyone used to believe that thinner strings were better, but that's kind of changing now. Many people now think, especially with the polys, that thicker gives you more spin. The idea was that thinner strings would dig into the ball deeper, "biting" it more - now the idea is that thicker strings make the string bed "rougher".