Sampras is widely recognised as having one of if not the best second serve of the modern era. But which women had the best 2nd serve ? If you look at many of the big serving types like Venus Williams, they had unreliable second serves which broke down under pressure. On the other hand a person like Hingis with a relatively moderate 1st serve, relied on variety and accuracy. I can recall in a semi final of the AO she made 33 consecutive 1st serves in play. Hard to make double faults if you're that accurate. So who's the GOAT of 2nd serves ?