Grass is the one finicky surface for the women. The reason for that is it plays to the players who are the shot makers. You see less tampon upsets under that scenario where the true ballstrikers outhit their opponents as opposed to just getting outgrinded by some scrub playing ping pong and praying for errors. Case in point Brenge beat Kvitova on a hardcourt but plays her today on the faster surface and probably gets blown off the court, and thats even these Wimbledon courts playing slower than ever, it's still the fastest surface out there with the low bounce.