How many Grand Slam titles were won by the defending champion of the 1981 US Open - Women's Doubles?
1981 US Open – Women's Doubles Billie Jean King and Martina Navratilova were the defending champions but only Navratilova competed that year with Pam Shriver.
1981 Davis Cup The 1981 Davis Cup (also known as the 1981 Davis Cup by NEC for sponsorship purposes) was the 70th edition of the tournament between national teams in men's tennis. This was the first year that the tournament moved to a tiered system, with the creation of the 16-team World Group. Teams that reached the Zonal semifinals in the previous year's tournament were chosen for the inaugural World Group. Teams who lost in the first round played each other in the Relegation Play-off, with the four losers relegated to their Zonal competition. Winners of the Zonal competitions earned promotion into the next year's World Group. 53 teams would enter the competition, 16 in the World Group, 23 in the Europe Zone, 8 in the Americas Zone, and 6 in the Eastern Zone. The United States defeated Argentina in the final, which was held at Riverfront Coliseum in Cincinnati, OH, United States, on 11-13 December.