Premise: The 1987 Federation Cup was the 25th edition of the most important competition between national teams in women 's tennis . The Grand Slam tournaments , also called majors , are the four most-important annual tennis events . 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 . Her 22 singles titles put her second on the list of Major wins by a tennis player ( male or female ) since the introduction of the Open Era in 1968 and is third all-time behind Margaret Court ( 24 ) and Serena Williams ( 23 ) .
Hypothesis: Steffi Graf is incapable of being a tennis player.
Label: CONTRADICTION