Martina Navratilova is a person.
The 1975 Federation Cup was the 13th 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 . Martina Navratilova ( Martina Navrátilová [ ˈmarcɪna ˈnavraːcɪlovaː ] ; born Martina Šubertová [ ˈmarcɪna ˈʃubɛrtovaː ] ; October 18 , 1956 ) is a Czech and American retired tennis player and coach . Over five consecutive seasons , she won 428 of 442 singles matches , averaging fewer than 3 losses per year to 87 wins , for a sustained winning percentage of 96.8 % . She was ranked in the world 's top 10 in singles for a record 20 consecutive years ( 1975 -- 1994 ) , a span which included 19 years in the top 5 , 15 years in the top 3 , and 7 years as the world No. 1 ranked singles player .