Premise: The 1987 Federation Cup was the 25th edition of the most important competition between national teams in women 's tennis . Christine Marie `` Chris '' Evert ( born December 21 , 1954 ) , known as Chris Evert Lloyd from 1979 to 1987 , is a former World No. 1 professional tennis player from the United States . Margaret Court ( née Smith ; born 16 July 1942 ) , also known as Margaret Smith Court , is a retired Australian tennis player and former world No. 1 . Stefanie Maria `` Steffi '' Graf ( [ ˈʃtɛfiː ˈgʁa : f ] ; born 14 June 1969 ) is a German former tennis player , who was ranked world No. 1 during her career . She won 107 singles titles , which ranks her third on the WTA 's all-time list after Martina Navratilova ( 167 titles ) and Chris Evert ( 157 titles ) .
Hypothesis: Steffi Graf is incapable of being a tennis player.
Label: CONTRADICTION