Billie Jean King wasn't #1 but one of the founders of WTA together with Margaret Court who wasn't an official WTA #1. Only Vika, Kim, Venus and Steffi were missing. Since the WTA began producing computerized rankings on November 3, 1975, 21 women have reached the highest singles ranking.The first one was Chris Evert who held that ranking for 21 weeks returning later ending up with a total of 260 weeks as number one - quite impressive, but still she is only 3rd!