At the age of 41, one of the sport's, and sport's, most celebrated, and, yes, loved practitioners was out of the big arena. 

Nobody remotely doubts that Federer - family man, ideas man, corporate advertising dream man - will continue to thrive in whatever new areas he chooses to direct his talent and ambition.

But as the reverberations of his departure lessen, the question arises: just how does he stand among the all-time greats?

When Federer won his sixth Wimbledon title in 2009, aged 27, he surpassed Pete Sampras's record of 14 men's Grand Slam singles titles. He went on to add two more Wimbledon titles - a record - and five more Grand Slam wins in all, the last of which was the Australian Open in 2018.

As his capacity to win big events was diminished by persistent back and knee problems, his main rivals, Rafael Nadal of Spain and Serbia's Novak Djokovic, were building their own remorseless totals, and now both have passed the Swiss player's mark of 20.

Nadal, who sat in tears alongside Federer after partnering him in his last match, and later insisted: "An important part of my life is leaving too", now tops the list on 22, with Djokovic, a year younger than the Spaniard at 35, on 21 wins.

In terms of bare statistics, Federer is not the greatest male player. But statistics can only tell you so much.

Looking down that list, past Sampras, you see among others Roy Emerson on 12, Rod Laver and Bjorn Borg on 11, Ken Rosewall, Ivan Lendl and Andre Agassi on eight, John Newcombe, Mats Wilander and John McEnroe on seven.

Statistics can only tell you so much - as Federer himself will tell you. 

Reflecting upon his record shortly before his final outing in London, Federer recalled the 2009 Wimbledon victory over Andy Roddick, achieved after a stupendous struggle with a fifth-set margin of 16-14. 

The gutsy Roddick, who had lost to Federer in the 2004 and 2005 Wimbledon finals, played out of his skin; and never came closer to a Wimbledon title. But on the day human had to give way to super-human as the Swiss player become the history man…

"Anything after that was a bonus," Federer said. 

"Obviously the last few years have been what they have been, but I’m very happy that I was able to win another five slams from 15 on. For me it was incredible. Then I made it to over 100 titles, and all that stuff has been fantastic.

"Then just my longevity is something I’m very proud of. Don’t need all the records to be happy; I tell you that."

There was some irony in the fact that the end of Federer’s stellar career should occur in the Laver Cup, an event pitting Europe against the Rest of the World that he himself conceived of in 2017 and which is named in honour of the Australian player whom many observers of tennis still feel has a claim to the unofficial title of The Greatest.

Hopping back to the stats, while Laver won 11 Grand Slams, he was banned from playing those tournaments for five years prior to the arrival of the Open era in 1968. He won 11 of the 16 Grand Slams he contested. He is also the only player, male or female, to have twice completed "the Grand Slam", that is, winning all four main titles in the same calendar year, something he achieved in 1962 and 1969.

Among those who would champion Laver’s historical pre-eminence is Ron Atkin, who has reported and written about tennis for around 50 years, and is a former Tennis Correspondent of the Observer, the Sunday Telegraph and the Independent on Sunday.

"In the league table of 'who’s the best'", Atkin, now 90, told insidethegames, "he is certainly up there with the greats, not quite perhaps Borg and McEnroe in their pomp - or indeed Laver - but certainly the best until his announcement of retirement at 41.

"The only comparable female I can think of is Steffi Graf, since he is not in the same league as Martina Navratilova."

In purely statistical terms, let us remind ourselves, the list of female Grand Slam winners is headed by Australia’s Margaret Court, who won 24, and another legendary tennis talent who has retired this year, Serena Williams, who finished on 23, one more than Graf.

Helen Wills Moody won 19 titles between 1923 and 1938. The - to Atkin - incomparable Navratilova is on 18 wins, along with Chris Evert. Billie Jean King is next with 12…

Another view on Federer has been afforded to insidethegames by one of Atkin’s successors as Observer Tennis Correspondent, Kevin Mitchell, who covered the game from the early 1990s and also became the Observer’s Chief Sports Writer.

"Much as with the recently departed, widely admired Queen Elizabeth II, keeping perspective about Roger Federer can be tricky for anyone uncomfortable with mass adoration," Mitchell writes.

"There is no denying Federer’s tennis greatness. Beyond debate, the ageless Swiss has been the most aesthetically pleasing of all the game’s many thousands of players and, with his travelling companions, Nadal and Djokovic - not to mention the lauded giants of previous eras - he is on a different plane of excellence.

"Indeed, there is a YouTube selection of Federer’s best 100 points on the ATP Tour. It lasts more than 46 minutes. Each second, almost, defines his genius. Noticeably, however, the best shots are played against the best, as if he reserves gold for his peers, silver and bronze for the rest.

"It is not difficult to imagine members of the Church of Federer worshipping daily at this digital shrine.

"And yet, for all his gifts, his 20 majors and his Elizabethan longevity, there was another, rarely seen side to Federer. When Switzerland won the Davis Cup for the first time, beating France in the 2014 final, nearly all the questions were directed towards the great man, by a wide-eyed phalanx of fans masquerading as journalists.

"Suitably refreshed and brimming with mischief, Federer’s friend and rival, Stan Wawrinka, who had partnered him to win the doubles, interrupted the love-fest to observe, 'We all love you, Roger!'

"Federer, who had also dipped into the celebratory champagne, smiled back. They knew. A week earlier, they had nearly come to late-night blows at the O2 Arena after their match in the ATP World Tour Finals. It was a row sparked earlier by an on-court exchange between Wawrinka and Roger’s wife, Mirka, who was sitting nearby to a disputed line call. It was the most revealing of snapshots.

"There were one or two other revelatory moments. Asked once to list one of his outrageous winners at the Australian Open among his best-ever shots, he replied too hastily, 'Top 100.' The room laughed. Federer blushed. Too late, he recognised his minor gaff.

"Quibbling? Perhaps. But no monarch rules without dissent or question; surely better the whole picture than the stamp-sized portrait. Anyway, the enduring image, as he disappears gracefully into retirement, is powerful enough to erase any minor blemishes."

Federer’s "genius", as Mitchell describes it, is something which has been remarked upon by some of the game's outstanding figures.

His versatility was memorably evoked by Jimmy Connors, who amassed eight Grand Slam wins between 1974 and 1983: "In an era of specialists, you're either a clay court specialist, a grass court specialist, or a hard court specialist... or you're Roger Federer."

McEnroe has referred to Federer's forehand as "the greatest shot in our sport."

One of the journalists covering Federer’s farewell, Isabelle Musy of Radio Télévision Suiss, has known and written about him for longer than most, having reported his matches since he was 17.

"He will remain an iconic tennis player of all-time, even if he’s not going to have the most titles, because of what he has brought to the sport of tennis and what he represents on and off the court," Musy told insidethegames.

"His career and results were fantastic, he has even invented some shots.

"His style is just unique. I think that will keep him at the top anyway, or among the top players, even thought some younger players may be better, he will remain as an iconic player for the sport. I think everyone will agree with that.

"On top of that, his human side is something that people praise. I was talking about that yesterday with his mother. People praise him not only for what he has achieved as a tennis player, but as a human being.

"All the players I have been interviewing these past few days, they all say the same - what a great human being he is, the attention he has for everyone, the relationship he has with people, how he behaves when he’s talking to people…

"I think he gradually became what he is. When he was a teenager sometimes he would lose his temper and everyone would know. He wasn’t behaving badly, he was behaving like a teenager. One thing that has always been there - he has always been very emotional and very sensitive. That was from the very beginning.

"When he left his school to do his studying at the national tennis centre his teachers recalled that he would be very emotional. He could cry in a classroom if he had a bad grade. He has always been very sensitive.

"But he has learned through the years to be more composed and to behave well. I mean his parents told him to behave better on the court when he was young. They didn’t like it when he would throw a racket away or something like that. He would throw his racket when he was still leading. But he was a teenager. Nadal would do the same.

"I think his wife Mirke helped him a lot with that. He says that she was always telling him how to behave and she has played a big role in what he has become."

McEnroe retired aged 33. Bjorg retired - despite a later unsuccessful comeback - at 26. Federer has continued at the top level until 41.

This is one of the reasons why he is on the world marathon record holder Eliud Kipchoge’s list of those from other sports who have been role models.

Speaking a week before his run in Berlin today, where he took 30 seconds off his own marathon world record at the age of 37, Kipchoge reflected upon Federer’s recent announcement of imminent retirement.

"I get inspiration from a lot of athletes in other sports," he told insidethegames. "I am looking for Roger Federer as far as tennis is concerned. He is one of those who has handled themselves so well to be at a high level for a very long time.

"Let me start by wishing him all the very best as he is venturing into other things as far as human life is concerned. I wish him well and his family well.

"In the front of my mind it’s good to see someone who has been high , high, high and having a huge following, retiring and venturing on other things. That was a big inspiration to me, to still push, but one day I will hang up my shoes and do other things. Even when you are as high as he is, it needs to have an end when you have a family.

"Roger has been a really tremendous inspiration to all the world. And I think the world will remember him for promoting the sport across the whole world."

Everyone has their own favourite players who are celebrated for achievements, or moments, that will always arise in recollection. So much of the appreciation of tennis players, or indeed sporting figures in general, comes down not so much to what they did as the way they did it.

Reflecting upon the career of Roger Federer one is put in mind of the quote by the late Northern Irish footballer Danny Blanchflower, who captained Tottenham Hotspur to their historic League and FA Cup double in 1960-1961: "The great fallacy is that the game is first and last about winning. It is nothing of the kind. The game is about glory, it is about doing things in style and with a flourish…"