I had many discussions about this over the years. The difference is I was playing tennis and did actually play with top 100 girls and so forth.
When I was playing MY best tennis, I could beat let's say Serena without much effort. Top women's players are weaker than any ranked male. They are at the level of good male club players. They hit the ball well. But they are slow. It does not matter if you can hit a ball if you don't get to it in time.
When I played squash, I dated Courtnay Powers. She was top something in the world if I am not mistaking and we played a few times together. I would manage to take a set off of her but she always beat me in the end. It's like she was playing with a yo yo sending me all over the court. With fresh legs and going for shots I could take a set. But she won the matches. The only time a girl beat me at something I thought I was good at 
I also played once for fun with her brother and former world No 1 Jonathan. I thought it was a very cool experience.
See, without me actually coming up here for Sev, he's correct. If he was even a mildly competent player, he'd give the world nr1 female a massive go. Maybe even beat her. There's such a big difference between males and females with regards to pace and power. And most importantly, movement. Compared to males, females move as if their feet are stuck to velcro.
I know some people likes to rag on anyone here that did/does something out of the norm or of note, but this is just the truth.
Even today, having not picked up a badminton racket for 10 years, I'd give the world nr 1 female badminton player a massive game. She'd beat me but she'd have to work for it.
Such is the difference.
