John McEnroe was a tennis player.
The Association of Tennis Professionals ( ATP ) was formed in September 1972 by Donald Dell , Bob Briner , Jack Kramer , and Cliff Drysdale to protect the interests of male professional tennis players . The Grand Slam tournaments , also called majors , are the four most-important annual tennis events . John McEnroe . He won seven Grand Slam singles titles ( three at Wimbledon and four at the US Open ) , nine Grand Slam men 's doubles titles , and one Grand Slam mixed doubles title . The Championships , Wimbledon , commonly known simply as Wimbledon , is the oldest tennis tournament in the world , and is widely considered the most prestigious . The United States Open Tennis Championships is a hardcourt tennis tournament .