FILE - In this March 17, 1977, file photo, Rosie Casals of Sausalito, Calif., catches up with the ball for a backhand return during her match with Mary Hamm at the Virginia Slims tournament in Philadelphia. Casals won, 6-2, 6-4. It’s the 50th anniversary of Billie Jean King and eight other women breaking away from the tennis establishment in 1970 and signing a $1 contract to form the Virginia Slims circuit. That led to the WTA Tour, which offers millions in prize money. Casals was one of then nine. (AP Photo/Rusty Kennedy, File)