 Although Suzanne Lenglen was the leading player in the first year of the professional circuit, after she retired in February 1927 very few female players played on the professional circuit before the Open Era.In the years before the Open Era, professionals often played more frequently on head-to-head tours than in tournaments because tours paid much better than tournaments and the number of professional tournaments was small.For example, Fred Perry earned U.S. $91,000 ($ today) in a 1937 North American tour against Ellsworth Vines but won only U.S. $450 ($) for his 1938 victory at the U.S.