the drought of tennis movies

With Friend Pamela staying at the casa for a bit, it's only fitting that, particularly with Wimbledon happening, ESPN suddenly gets a workout where once it did not.  If I could personify channels, I would say the surprise of its sudden use has rendered ESPN virtually exhausted.  But with all this tennis extravaganza, it got me thinking.  How is it that such a popular and age-old sport hasn't been put to film more often?  From my searching, it seems there have been only two mainstream flicks to do with the court sport - Wimbledon and Match Point.  Sure, there have been some obscure, probably beloved-by-tennis-philes movies, but how have we not had a biopic or two out of the great potential.  John McEnroe's fiery temper, Arthur Ashe's groundbreaking star status, the phenomenon that is the Williams sisters - they all lend themselves to this big-screen treatment.  And with the death of the network telefilms, will we ever see another When Billie Beat Bobby?  Or perhaps I'm not deep enough in the tennis world to know of all the niche films.  Educate me - and perhaps inform, if you're a tennis fan yourself.