By 2012, the three horsemen of men’s tennis won everything, couldn’t be beaten by anyone but each other, and dragged the sport into the future with whirling top-spin forehands and impossibly precise backhands. They expanded what tennis perfection could be, and I felt I needed to choose a side in the arms race.

It was not easy for Rafael Nadal to call it quits, but he knew it was the right time. The 38-year-old tennis superstar announced his