McEnroe and Borg played each other 16 times in one of the sport's biggest rivalries, including in the finals of Wimbledon and the U.S. Open in 1980 and 1981.

In the late 1970s, professional tennis held a firm grip on the United States, and no two players better personified the sport's growth than cool-as-ice Swede Borg and brash New Yorker McEnroe.

Borg weighed in as well, noting: "I'm kind of a private person, I'd sit there and do my thing, but he [McEnroe] was the same. He didn't say a word in the locker room.