Sporting rivalries are not supposed to be like this. Mike Tyson may have gone to extremes when he bit off Evander Holyfield's ear, but in the world's great sporting arenas you always expect an edge to confrontations between the best of the best. You could never picture Sebastian Coe and Steve Ovett sharing a joke before or after an Olympic final or Ayrton Senna and Alain Prost leaving a grand prix to go for a drive together in the country.
Yet when Roger Federer and Rafael Nadal walk out on Centre Court tomorrow for their third successive Wimbledon final there will be no snarling, no avoiding eye contact, no cold handshakes. In any sport you hope that the two outstanding competitors of their generation will show mutual respect, but the relationship between Federer and Nadal goes beyond that.
A senior executive from the Association of Tennis Professionals who is close to both players has watched their friendship develop. "They're much closer than they were two years ago," he said yesterday. "They always had a lot of respect for each other, but that has developed into real friendship. I've never seen such a relationship between the No 1 and No 2 players in the world. They spend a lot of time together at tournaments and they chat a lot in the locker room. They even practise together sometimes."
The emergence of Novak Djokovic had been threatening to turn the top of the men's game into a three-way contest, but the last month has seen a reaffirmation of the top two's supremacy. Djokovic would have replaced Nadal as world No 2 had he won their French Open semi-final last month, but the Spaniard won in emphatic fashion before beating Federer in the final for the third year in succession.
While Djokovic went on to lose in the second round at Wimbledon, Federer and Nadal won their semi-finals yesterday to keep what is becoming an annual appointment on Centre Court. It will strengthen their hold on the top two places in the world rankings. Federer has been No 1 for a record 231 consecutive weeks; Nadal, whose ranking points total would have earned him the No 1 spot many times in the past, has been No 2 for 153 weeks in succession.
The irony is that Nadal has won 11 of his 17 meetings with Federer, even if 10 have been on his favoured surface of clay, on which the Swiss has beaten him only once. Nadal has never beaten Federer on grass, but has twice beaten him on hard courts.
Federer, 26, is only two Grand Slam titles short of Pete Sampras' record of 14 and plans to play beyond the 2012 Olympic Games, when the tennis will be staged at Wimbledon. Nadal, 22, has not won a Grand Slam title away from Roland Garros, but his four French Opens look sure to be only the start of his collection. The 2008 Australian Open, won by Djokovic, is the only Grand Slam tournament that has not been won by one of the top two since January 2005.
There have been other golden eras, such as the Rod Laver-inspired years of Australian domination in the 1960s and 1970s and the great days of Bjorn Borg, John McEnroe and Jimmy Connors in the 1970s and ’80s, but Federer and Nadal could eclipse anything that has gone before. Many would already acclaim Federer as the greatest player of all time and when Nadal starts winning Grand Slams on anything other than Parisian clay we may start talking about him in similar terms.
Marat Safin, beaten by Federer yesterday, has no doubt about how they will be remembered. "The two of them will be the greatest players in history," the Russian said. "Nadal hasn't lost a match on clay since I don't know when and Federer is going for his sixth Wimbledon. I think he's definitely going to break the record for Grand Slam titles. I hope he does so that I can tell my kids I played against him. They're just two great guys, really down to earth. Federer is quite funny, as is Nadal. It's good to be with them in the same locker room."
One of the joys of their rivalry is the contrast of styles. Federer, the ultimate artist, has all the shots, always looks unruffled and floats across the ground with the ease of a skater on ice. Nadal, muscles rippling, crashes the ball across the net with unrivalled power, charges around the court with phenomenal speed and never looks tired. While Federer has reigned supreme on grass and Nadal has ruled on clay, they have proved themselves the second best on each other's favourite surface.
"Nadal could wake up at three o'clock in the morning and go out and play on clay," Borg said yesterday as he looked ahead to tomorrow's final. "He knows exactly what to do. On grass it's different for him. He has to rediscover his own style on grass, where you have to be that bit more aggressive. It's not like that for Roger. Playing on grass is natural for him. He feels so comfortable"
Having come so close to beating Federer in last year's final, Nadal has shown such improvement on grass that many, Borg included, see him as the favourite this time. "He's improved a lot from last year, though I've no idea where he found the time to do that," Borg said.
"He's improved his serve a lot. His placement is better and he's hitting the ball a bit harder. His backhand slice and volleys are better and he's playing more aggressively. I also think he's moving a lot better on grass."
McEnroe is among those astounded by the speed with which Nadal has become such an accomplished grass-court player. "It's pretty amazing, considering that his serve seemed to be a bit of an issue and, like most clay-court players, he wasn't coming in a whole lot," McEnroe said.
"He didn't seem that comfortable at the net. Obviously Borg made this transition, but you didn't know how well Nadal would make it in terms of his movement. But it turns out that he likes the movement on grass almost as much as clay."
Borg does not believe that defeat tomorrow would be the beginning of the end for Federer. "I think Roger wants to break every single record that's out there," he said. "He's very determined, very professional, very motivated and I think he'll play for at least five more years and be world No 1 for many more years to come. I believe he'll win many more Grand Slam tournaments and Wimbledons. If he stays healthy and keeps his motivation I think he can win between 15 and 20 titles."
Federer and Nadal have played each other in so many finals that it is easy to forget that they first met only four years ago. The Spaniard won their first Grand Slam encounter in the French Open semi-finals a year later.
The seeds of what was to become an outstanding rivalry were sewn in 2006, when Nadal beat Federer in four successive finals in the spring at Dubai, Monte Carlo, Rome and Paris. Federer's subsequent victory in the Wimbledon final established a pattern for their rivalry that has hardly changed since, with Nadal usually reigning on clay and Federer doing so elsewhere.
"Rafa is a great competitor," Federer said yesterday. "He's got a great winning record against me, but I've played him so often on clay that it's given him an advantage in our head-to-head record. At the same time he's become so good on all other surfaces that he's a real threat to me and everyone else. But we'll see what happens between now and the rest of the season because this is my favourite part of the year."
Borg sees a parallel with the rivalry he shared with McEnroe. "Federer and Nadal are friendly. They respect each other, as John and I did, both on and off the court. We knew that we produced good tennis every time we played. What Nadal and Federer is doing is great for the sport. They're playing unbelievable tennis that everyone can enjoy, on any surface.
"They push each other. They know they have to be at their best when they play each other. And at the same time I think they enjoy playing each other because they know they're pushing each other to their limits to play their best tennis, like John and I did."
While McEnroe and Borg had mutual respect, other rivalries of their era were less than friendly. McEnroe and Connors in particular were often at loggerheads. The latter found it hard to accept the young upstart taking his crown and once told McEnroe at a changeover that his two-year-old son was more mature.
McEnroe, who never looked more despondent than when Connors beat him in the 1982 Wimbledon final, found it hard to deal with Connors reinventing himself in his later years by playing to the crowd. The rivalry between the two mellowed only towards the end of their careers when they found a common enemy in Ivan Lendl, whose cold and ruthless manner they both found hard to understand.
Most of the relationships from that era are a far cry from the genuine friendship that Federer and Nadal have established. Although they rarely socialise outside the tennis environment - Federer is probably closest to his fellow Swiss Stan Wawrinka and was also good friends with Tim Henman, while Nadal spends time with Juan Monaco, Carlos Moya and Feliciano Lopez - they regularly enjoy each other's company at tournaments.
"I think a lot of it is to do with the way they've been brought up," the ATP insider said. "They come from the same sort of social background. Families are very important for both of them. The families are very similar. They're often around at the big events but they're never pushy. They keep out of the spotlight.
"I remember Roger's parents coming to Indian Wells last year. They said they'd come to play golf. I'm sure they would have watched Roger, but he got knocked out in his first match. Then when they came to Madison Square Garden to see him play Pete Sampras in an exhibition event I remember his mother saying that the reason she was there because she'd never seen Sampras play.
"Mirka [Federer's girlfriend] goes to every tournament with him and she's there on court whenever he plays, but she often doesn't come on site on a day off when he's practising. She has her own life. And you don't see Rafa's girlfriend around that much. She's a student and obviously can't spare the time away from her studies. His parents and sister often come, but again they very much keep in the background."
Both players take their role as leading players seriously and have been joined by Djokovic on the ATP's player council. Last year it was Federer and Nadal who led a players' revolt against planned changes in the calendar which would have seen a downgrading of some of the traditional European clay-court events.
"I've always tried to get the players together to talk about what we would like to have happen for the tour," Federer said. "Especially thanks to Rafa, I think we've established a very good relationship over the last few months and years."
Nevertheless it will be on the court that Federer and Nadal continue to have the greatest impact and Borg for one is delighted that they have made it through to tomorrow's final again. "For me to see those two guys is the best thing I could wish to see as a spectator and a former player," he said. "It doesn't matter who wins. You just know that it will be an unbelievable tennis match."