Women's tennis: Why only three sets?

[wadea]

In this day of gender equity and Title IX, why in the world are women's tennis matches still best of three sets? Does anyone really believe that they lack the stamina to continue? Disregard the fact that nobody's watching anyway.

And another nit-picky note: Why is 30-30 never called deuce when it plays exactly the same as deuce i.e. you need to win two points in a row to win. 40-30 should be called advantage server since the server will win the set with the next point. Yet, for some reason they only use the term deuce when the score ties at 40-40. More evidence that I should be in charge of everything.