Martina Navratilova is an athlete.
The 1975 Federation Cup was the 13th edition of the most important competition between national teams in women 's tennis . The game that most people call tennis is the direct descendant of what is now known as real tennis or royal tennis ( which continues to be played today as a separate sport with more complex rules ) . Martina Navratilova . She holds the best season win-loss record for the open era , 86-1 ( 98.9 % ) in 1983 , and four of the top six open era seasons .