Three years ago, when I was doing research for my book High Strung, I came across a scouting report that Tennis Magazine ran in the mid-1970s on the promising young American players of that moment. A teenage John McEnroe was among the prospects, but he wasn't at the top of the list, or even near the the top. For all of his artistic skill, the slouchy lefty was never a dominant junior; in those days, he typically played second-fiddle to someone named Van Winitsky. But young Johnny Mac had something that caught people's eye. His coach, Harry Hopman, often said he would be No. 1 in the world someday. Tennis wasn't that prescient, but its scouts weren't wrong about McEnroe, either. They said he was the most gifted of the new crop, and that he could be the best of them, if he used those gifts wisely. The implication was, he might not...
Atsushi Tomura/Getty Images