I can buy Andro Rasanter R37, 42, 47, 48, 50, 53, C45, 48, 53 today - if a pro happens to have 52 or 55 sponge, how can it be said that this is "significant" variance?
BTW, is there any requirement in racket control to take off a players rubber to measure sponge hardness?
Remember the OP of...