Elite genetics. Did you know that Zack Greinke was a tennis prodigy? You have quick twitch muscles, or you don't. Hard work will leave you broke and paying your way through the Challengers Tour.
I can personally assert I am very familiar with how WTA careers are developed and financed. For one, you need a ton of $$$$. Mainly because you won't even hope to break even only playing ITF level events due to travel costs. You basically need to make the top 80 to have a career that even makes you money. And it'll take a few years to gain enough points to make it that high.
Before getting to that point, you obviously gotta be a great player. And the only way to become a great player is to practice against other great players - and that usually happens in the US at Nick Bollatieri's Academy or Chris Evert's Academy. Pay the tuition and go there (or if you are a prodigy maybe they give you a scholarship).
Most of the state HS tennis champs from the northern states play no competition. So they aren't actually getting better even though they are winning lot of matches in their states. Tennis is the one sport where you can't really become great by only doing drills by yourself. You have to play elite competition. I'd say tennis is the hardest sport to make a living at. Being top 80 in the world is nearly impossible task given Tennis is a world wide sport. But there are stories of women in their 30s finally breaking thru like Buznarnescu or even Mandy Minella.
If you got alot of cash you can certainly chase the dream. Lot of the tennis girls are rich country club girls blowing thru daddy's money till they turn 20/21 and realize slumming it on 3rd world clay shit holes isn't a very glamourous life and then give up and do something else.
As for mens side, if you want inspiration look up Diego Schwartzmann. If he can make it from how he started (5'6, poor, playing shit level Futures events). anyone can.
wow. Thanks guys I appreciate the info. My nephew has fallen in love with tennis and says he wants to be a pro. Now I know its a long shot but I figure if he works hard and has a dream he can at least play college tennis as consolation prize and then everything else will be icing on the cake.
Tennis lessons at a very early age to start, tennis camps then after, go to the best schools for tennis.. Tennis leagues, then live and breathe tennis daily..
Make sure you got to a very good Tennis based High school like we have here in Los Angeles, California... Become the #1 tennis player at your high school, get a scholarship to a good tennis College like UCLA after that.. Dominate and go Pro then after..
That's what I would have done if I could have a do over.. I went for Volleyball and Basketball also and it was to much to master them all. Just ended up being really good at all 3 sports but a master of none... I never focused on just one sport in other words growing up.. Big mistake...
Just sharing my potential pro life story.. .. I had the physical gifts...