In many ways, tennis is the ultimate individual sport and to excel requires three qualities in equal measure.

Obviously, you’ve got to be fit. But you can’t just be fast, reactive, and strong. You’ve got to have stamina and stickability. Tennis players are finely balanced athletes. There’s no point being big and strong if you can’t last three (or five) sets. And there’s no point lasting five sets if you don’t have the strength to hit a few winners along the way.

The World’s best tennis players have extraordinary technical skills. The sport demands supreme hand-eye co-ordination, timing, vision, and the mastery of a simple but extremely powerful tool.

And perhaps above all, ythe World’s best need an incredible mental edge. In Grand Slam tournaments, players cannot be coached during their games. They rely only upon themselves to shoulder the insane pressure of life-changing moments in life-changing matches, the huge ups and terrible downs of a game’s shifting momentum.

No player has impacted the sport of tennis quite like Serena Williams.

But no one has played tennis like Roger Federer.

One of my favourite-ever pieces of sports writing is a feature on Federer by the late American literary hero, David Foster Wallace. The author was a tennis prodigy as a kid, and he sought to describe the Federer ballet not just as an athletic contest or a ticket to multi-million-dollar electrolyte endorsements, but as a form of human beauty that transcended sport.

“Federer’s forehand is a great liquid whip, his backhand a one-hander that he can drive flat, load with topspin, or slice — the slice with such snap that the ball turns shapes in the air and skids on the grass to maybe ankle height. His serve has world-class pace and a degree of placement and variety no one else comes close to; the service motion is lithe and uneccentric, distinctive (on TV) only in a certain eel-like all-body snap at the moment of impact. His anticipation and court sense are otherworldly, and his footwork is the best in the game.” – Roger Federer As Religious Experience

I spent an afternoon once with the Nike footwear designer who worked with Roger Federer to design his playing shoes. The designer told me he’d been surprised to discover how unusually wide Federer’s feet are. It makes sense when you think about it – wider feet presumably allow a player to balance and change direction, to set himself, much more efficiently than someone with narrower feet. Federer popularised several tennis shots in top level tennis: the so-called squash shot, and the SABR (Sneak Attack By Roger) in which he surprised his opponents by running up to the service box just as their service toss hung in the air. But it his was balance that made that magnificent backhand so glorious, so perfect.

I was lucky to see Federer live at several Grand Slams over the years. He hasn’t been at his best for some time now, and his retirement was inevitable. But sometimes if I’m home alone, I’ll still watch highlights of his greatest moments on YouTube. It’s like sitting in a room with Beethoven as he knocked out his sixth symphony.

Fluid. Dazzling. Genius.