Who is the best tennis player in the world?
Probably Steffi Graf, after all she is the only player who has ever won the grand slam tournament 4 times!
I would agree with you on that. Didn't she marry another professional athlete?
Yes, Andre Agassi, another extremely talented tennis player! He was number 1 in the nation for a period!
Who is the top ranked tennis player in the world right now?
For men's tennis it is Rafael Nadal of Spain! Do you know who the top ranked player is for women?
I do not. I only remember some older names like Kournikova 
She is very well known, but as of 2000 she was number 8 in the world, which is still impressive