The tune ups are Indy, LA, DC, Montreal, Cincy, New Haven for the Men
and Stanford, LA, Cincy, Toronto, New Haven for the Women.
Top points earners stand to make a big bonus if they win the US Open.
Kim Clijsters and Roger Federer are the only ones who have won the
million dollar bonus.
At least among the men, the top players from outside the US play only at
the mandatory events.
Staying fresh for the slams is as important at tuning up your game.
Last year's series winners:
Nadal, Murray, del Potro
Safina, Bartoli, Cibulkova
Got to support the comeback (with) kid: Kim Clijsters!