THERE is no perfect way to retire from elite sport, but this weekend Roger Federer has ensured he has got as close as is possible to the perfect valediction.

In drawing the curtain for the final time in what has been a remarkable career, there was no better way to go out than in playing doubles alongside Rafa Nadal.

The pair had one of, if not the greatest, rivalry in the history of sport, never mind merely tennis.

A truly great rivalry requires contrast and on the doubles court at the Laver Cup in London on Friday, their difference as players was as clear as it has been throughout their almost two-decade-long careers.

Nadal is a physical beast; his sleeveless tops may be no more but his physicality and intensity remain as obvious as ever.

What made Federer so remarkable, though, was that he has never had that overt physicality, yet was able to match the Spaniard on court.

While Nadal makes tennis at this level look effortful, Federer makes it seem effortless.

That is not, of course, to dispute that the Swiss is one of the greatest athletes to set foot on a tennis court. Rather, he made the sport look so graceful that it was easy to assume he was not, in fact, running himself into the ground. That he never seemed to break sweat, even in the most humid of conditions, was a feat in itself.

While talent is subjective, no one would dispute that Federer is one of the most gifted players ever to pick up a tennis racquet. He did things on court that left crowds stunned.

To watch Federer, particularly in real life, was to witness something exceptional. While there is always something awe-inspiring to witness any individual who is amongst the best in the world at their sport, to see the Swiss work his magic was something else altogether.

To observe Federer glide around a tennis court, flicking his wrist and finding angles that seemed to defy logic was like watching an artist at work.

He had an arrogance – and that’s not a criticism – that all top athletes must have but he managed to carry it in a way that did not turn people off.

His genuine friendship with Nadal helped immensely. This is almost unheard of when it comes to two individuals competing for the biggest prizes in their sport.

Often, athletes benefit from harbouring a dislike for their opponent; animosity can be the surest way to bring out the best in so many sportspeople.

But Federer and Nadal were able to have a friendship off the court, while still retaining a desperation to defeat each other on it. To separate the two is almost impossible, but the fact they managed it is perhaps just further testament to their greatness.

The debate about who is tennis’ GOAT – the greatest of all time – is never-ending.

On the men’s side, there are legitimate arguments for Federer, Nadal and Novak Djokovic to all lay claim to that title.

If it is purely a numbers game, it cannot be Federer. His haul of 20 Grand Slam titles has been overtaken by both Nadal and Djokovic, who are on 22 and 21 respectively.

But greatest-ever is not based exclusively on statistics.

Federer’s style of play was, in so many ways, a form of art. This is why he was showered with such adoration by crowds across the globe, even when he was playing one of their own – something Andy Murray knows only too well from his experience, at times, at Wimbledon.

What is more remarkable from Federer: his period of dominance between Wimbledon 2003 and the Australian Open in 2010 during which he won 16 of the 27 Grand Slam titles on offer (and reached the final of a further six), or his final major title, at the age of 35 having been absent for the previous six months due to knee surgery, in 2017 at the Australian Open, when none but the most ardent of fans thought he would claim another Grand Slam?

For me, despite his out-of-the-blue heroics in Melbourne 2017, it is his period of dominance, which is so difficult to achieve in any sport, that is most impressive. But there is no definitive answer to the question of which part of his career was his greatest.

The departure from tennis of Federer, just weeks after Serena Williams hung up her racquet, shines a light on the fact that this era of tennis, spanning the past decade and a half, is coming to an end.

Nadal likely has a couple more seasons in him, Djokovic perhaps a few more. But soon, these giants of modern-day tennis will have departed the scene.

Can tennis scale these heights again?

Carlos Alcaraz, who claimed his maiden Grand Slam title at the US Open this month, appears to be the man to fill the gap left at the top of men’s tennis, but one man does not a rivalry make.

What has been so thrilling about this period is that Federer, Nadal and Djokovic forced each other to continue improving. Without each other, none would have scaled the heights they have.

Tennis will recover from Federer’s retirement. But will it ever surpass what we have seen over the past decade or so?

I wouldn’t bet on it.