Roger Federer slowly, lovingly, takes the wrapping off his new racket, like a little boy with a giant lollipop. “It’s my Wimbledon racket,” he says. He runs his fingers along the frame, bounces a hand against its head. He’s got plenty of rackets, of course – he’ll sometimes use nine in one match – but this is the one he’ll start with. With a bit of luck, he says, it could last him five years.

He passes the racket to me – it is light and not highly strung, which could also be said of the man. We are in a vast warehouse in Zurich, Switzerland, and I’m swinging away with the racket and imaginary balls. He looks lean, tanned, glowing, in the way only an elite athlete can. Federer has more time on his hands than he had hoped, after pulling out of the French Open with a back injury. He’s using the opportunity to launch a new clothes line – smart, spare, the kind of thing you’d imagine Federer wears in his down time.

We sit down to talk, and I hold on to his racket, hoping he’ll forget. He can’t focus. “Can I have my racket back, please?” he eventually says.

Federer was not always a respecter of rackets. Since winning his first major tournament, he has been known for his calm. He doesn’t shout at himself or his coaching team; he smiles rather than snarls on court; and he rarely questions decisions. The young Federer was a quite different proposition. He was an outrageously talented sportsman, at football as well as tennis, but he was almost undone by his attitude.

First Wimbledon win, in 2003. Photograph: Getty

He loved tennis from a young age, always playing against a wall at home, at a club with his Swiss father, a chemical engineer, and South African mother (Federer holds dual nationality). But when he started to compete, aged eight, he would get frustrated, berating himself, telling himself he was rubbish. “I wasn’t the angry type, I was always the sad and disappointed type.” Really? I heard he was a racket smasher. He smiles. OK, he was a bit angry. “But I’d throw the racket tactically, into the nets, so it wouldn’t break and I wouldn’t have to go to my parents, because it’s a lot of money. I’d commentate on each shot, saying, how in the world could I miss that, I can’t believe how badly you’re playing, this is just a joke.” For a second, he sounds like John “You cannot be serious” McEnroe. Tournament officials would tick him off for being too verbal, and tell him he was putting off other players. “My parents would get so disappointed in me and upset, they would just walk away.”

Could he have become a champion if he’d stayed that way? “Yes, but not to the extent I am today. I might have won a few slams, big tournaments, stayed in the top 10 for a long time, who knows.” He says this as if most of us were capable of a few grand slams. He grins. “Well, I’ve won 17, so maybe I could have won a few being a little bit cuckoo, but I’m not sure. You have to be mentally tough, physically strong, consistent, and I wasn’t. So I’m really proud I managed to turn it around.”

Jacket, £215, T-shirt, £95, and shorts, £100, all from the NikeLab Presents NikeCourt x Roger Federer: ‘Unlimited Class’ collection. Trainers, Federer’s own. Styling: Martina Russi. Grooming: Julia Ritter. Photograph: Mathias Braschler and Monika Fischer/The Guardian

Federer is missing his first grand slam in 17 years (there are four a year: the French, US and Australian Opens, and Wimbledon). He has played in 65 successive slams, a testament to his hunger and his fitness. Then there is his record. Or records. Federer’s grand slam total makes him the greatest male tennis player ever. His closest rivals, Pete Sampras and Rafa Nadal, have 14 each. The world’s No 1, Novak Djokovic, who has achieved the near-impossible this year of holding all four major titles at once, is coming up fast behind – but has only 12. To put Federer’s achievement in context, Andy Murray, Britain’s finest player since Fred Perry and world number two, has won only two grand slams.

Federer will be 35 in August. Most players his age have retired, but he is still ranked three in the world and believes he can win another Wimbledon.

It’s not simply his record that makes Federer the greatest, it’s the way he plays. Only once in a blue moon does somebody come along who transcends their sport, elevating it into a thing of beauty: Lionel Messi in football, Muhammad Ali in boxing, Ronnie O’Sullivan in snooker, and Federer. There’s the spirit with which he plays, and the elegance – the single-handed backhand, the driving forehand (his shirt rising to reveal his washboard stomach). Federer can match today’s baseline bullies, but he can also mix it up with the serve and volley that used to dominate the men’s game. His appearance is every bit as stylish. It wasn’t always that way: when Federer first emerged on to the scene, he looked fresh out of a teenage heavy metal band. But once he chopped off the ponytail he cut a different figure – more Jay Gatsby than Ozzy Osbourne.

For all the achievements of Nadal, Djokovic and Murray, no player is loved quite like Federer. In a famous essay for the New York Times, the novelist David Foster Wallace wrote that watching him play was akin to a religious experience. And in 25 years of interviewing, I have never had such a swooning reaction from friends and colleagues when I’ve told them who I’m meeting – young and old, men and women, Federer crushes know no bounds. One penny-pinching manager suggests he comes along to carry my bag. People give me hats, balls and books for signing. By the time we meet, I feel more like a merchandiser than a journalist. Even my mother warns me: “Whatever you do, don’t fall out with Roger.”

After his defeat by Nadal in the 2006 French Open. Photograph: Getty

Federer won junior Wimbledon at 16, but then his emotions kept getting the better of him. Other players realised he had a fatal flaw. “People knew, eventually he’ll crack,” he says. “Just stay with him and he’ll give you some easy mistakes. So I tried to create this aura of invincibility, of being tough to beat.” It took him a long time; Federer was almost 22 when he finally got the title.

So he had to move from being a tantrum-throwing McEnroe to a samurai-like Bjorn Borg? “To some extent, but Borg was all ice.” Federer’s heroes come from a later generation and are fiery types such as Goran Ivanisevic. When coaches told him he had to quieten down, he agreed, but only up to a point. “I said, I have to get my emotion out, I can’t handle it. They were like, yes, it’s good but not so much. Eventually I said, I need to find a balance. I can’t just be ice, it becomes horribly boring. I need the fire, the excitement, the passion, the whole rollercoaster. But I need it at a level where I can handle it: if I’m all fire, I go nuts. It took two years to figure that out. It was a long road.”

Federer says there is a story that Mirka, his wife and the mother of his children (two sets of twins, identical girls Myla Rose and Charlene Riva, who will be seven in July; and fraternal boys Lenny and Leo, two), tells about the first time she set eyes on him. “I was playing club tennis in Switzerland and everybody said, ‘Go see this guy, he’s super talented, the future of tennis.’ And the first thing she saw was me throwing a racket and shouting, and she was like [mockingly], ‘Yeah! Great player, he seems really good! What’s wrong with this guy?’”

Mirka was older and also a promising player, but very different: tough, disciplined, ascetic. She rose to number 76 in the world before having to retire in 2002 with a foot injury.

They met properly at the Sydney Olympics in 2000, where they were both competing. She was a mature 21, he was a young 18. “She’s always been older than me.” He means in every sense. That’s a huge difference at that age, I say. He nods. “When I kissed her for the first time, she said, ‘You’re so young.’ I said, ‘Well, I’m almost 18 and a half.’” He laughs. “You know how you try to shove another half year in? And she was like, ‘OK, you’re a baby.’”

Federer’s wife, Mirka, and twin daughters Myla and Charlene. Photograph: Rex



Federer says Mirka has played a huge part in his success. Look at the facts, he says. “When I met her I had zero titles, today I have 88, so she’s been on this ride for the whole time.” He talks of her with tender pride: how her parents fled communism in Czechoslovakia when she was only one, then struggled for Swiss citizenship, how she coped. She might not have realised her own dreams in tennis, but you sense she was his role model.

“She used to train five, six hours in a row. Her parents had to work extremely hard. She was tough, and she taught me how to work. I would be at the tennis centre and see her do six-hour sessions, and I’d think, I can’t do that. I’d check out mentally after an hour and go, this is so boring. So I’d get kicked out of practice for bad behaviour.”

There is a conventional wisdom, advanced by author Malcolm Gladwell and former British table tennis champion Matthew Syed, that natural talent gets you only so far: it takes elite performers 10,000 hours’ practice to fulfil their potential. Does this make Federer the exception to the rule? Has he achieved his success without putting in the hours?

God no, he says. He was always putting in the hours; just not necessarily in the right order and at the right time. Only when he put in Mirka-style stints did he start to fulfil his potential. Even then, his progress was hardly linear.

In 2001, he made headlines by beating Sampras at Wimbledon and reaching the quarter-finals; he also got to the quarters in the French Open, but the following year he was knocked out of both in the first round. “All of a sudden, people started to ask, where had the talent gone?” Was he worried he had thrown it away? “Yes, I was.” His parents (“the best I could have wished for”) and Mirka kept their faith in him, but he says the press began to ask whether he was psychologically flawed.

Back then, there was not such a gap between the world’s top players and the chasing pack; anything could happen. Part of Federer’s legacy is that he’s introduced a new consistency in the elite: today, the top four rarely go out of a grand slam before the semi-final unless they’re playing each other.

In 2003, he finally broke through, beating Mark Philippoussis in the Wimbledon final in straight sets, and over the next six years established himself as the greatest. There is barely a record Federer hasn’t broken: 10 consecutive grand slam finals, 23 consecutive semi-finals, 36 consecutive quarter-finals. He has spent 302 weeks as the No 1 ranked player in the world, 237 consecutively. He is the only player to have won two grand slams five times consecutively – Wimbledon (2003-2007) and the US Open (2004-2008). He is ranked fourth in Forbes’ list of the world’s highest-paid athletes, earning around $67m over the past year, $60m of that for appearance fees and endorsements. He has earned more than any tennis player in prize money alone: $98m.

I ask Federer which match has meant the most to him. He singles out three: the first time he beat Sampras, in 2001, because that put down a marker; his first Wimbledon win (“I’d achieved my dream and my career could stop right then, because all I’d ever wanted to be was a Wimbledon champ”); and his 2009 French Open victory against Robin Soderling (who had beaten Nadal in the fourth round). “That was the one slam I thought, maybe I’m never going to win it. When I did, I was so happy. Plus relief.”

Every final he lost at Paris was to Nadal. Did he think he was jinxed against him? “No. Sometimes I was outplayed, sometimes I was close, but never quite good enough to beat him at the French. But I never lost hope or faith that it could happen.”

Has Nadal been his greatest rival? “For me, he has been. It could still change if I play Novak another few times in bigger matches. Novak and I have obviously had really big matches, but somehow the match-up with Rafa will always stay unique – because of the Wimbledon final in 2008.”

That match verged on the biblical. In the end, Nadal won an epic fifth set 9-7. It began in sunlight and by the end seemed to be played out in a partial eclipse. Federer says he has found Nadal tougher to play than anybody, even Djokovic. “He’s a lefty – all that spin, we’ve not seen spin like that before. I had to change so many things to match him.”

In the fourth set, Federer was 8-7 down in the tie-break with Nadal serving for the match, when he played what is regarded by many fans as his greatest shot ever – a backhand pass down the line. It wasn’t simply the placing, or the power he achieved with that insouciant flick of the wrist; it was the courage of the shot. I ask Federer if there is a favourite shot he’s played. He struggles for an answer, so I mention this backhand. “Oh yes, that one’s good, but it didn’t come to mind because I ended up losing the bloody match. Who cares about hitting a great shot, then losing?”

He has an outlandish shot he loves, called the Sneaky Attack By Roger: charging into the net on an opponent’s serve

He prefers the passing shot he made through his legs in the semi-final of the 2009 US Open against Djokovic. It was deadly, audacious and witty – and it led to match point. Does he have a name for that shot? “No. People call it Hotdog, or Tweener, I call it the between the legs shot because that is just what it is.” Over the past year, he has developed another outlandish shot he loves, which he calls the SABR (Sneaky Attack By Roger), where he charges into the net on the opponent’s serve. “My coach encouraged me and I was like, it’s ridiculous. But he said no, you’re winning a lot of points like that. I started doing it at 15-15, then at break point, then the next thing is, it’s just another fun thing to do.” Few players have experimented the way Federer has, or enjoyed their tennis so much.

Yet since he was 20 he has played with immense discipline – the ice he talked about earlier. It is often only at the end of a tournament that we see his fire, and when it comes the explosion of emotion can be volcanic. His ability to weep after a final has surprised, and occasionally shocked, even him. The first time it happened, he says, he was playing for Switzerland in the Davis Cup against the US in 2001. “We beat the Americans in Basel, in my home city, where I used to be a ballboy. When I finally won the match I was so exhausted and happy, I broke down crying. And I was like, what is this emotion? I didn’t realise I had it in me.” A few months later he beat Sampras in the fourth round at Wimbledon. “I saved a break point and ended up winning 7-5 in the fifth with the forehand down the line winner, got to my knees, broke down again. I’m like, are you crazy? What is wrong with you?”

Just thinking of all this makes Federer well up again. Did it worry him? “No. I guess it’s one of the reasons I still play today, to relive those emotions.”

Federer’s through-the-legs shot in the semi-final of the 2009 US Open

He famously broke down after losing another epic against Nadal – the Australian Open in 2009. This time he was ashamed. “After losing a final, your head’s spinning and you just have to get through it, then you cry after you’ve walked out. But then the timing was horrible. This was Rafa’s moment and I took it away from him.” Was he angry with himself? “Yes, because it was so extreme. And so much was read into it. People saw it as a sign of my decline and, ‘Oh my God, he can’t accept he’s losing on hard courts now against Rafa.’”

After being beaten by Nadal in the 2009 Australian Open. Photograph: Getty

There is a lovely moment you can catch on YouTube, a short film Federer and Nadal shot for the Roger Federer Foundation, set up in 2003 to help disadvantaged children get an education. Every time Nadal speaks English, Federer gets the giggles because of his heavy accent. By the end, he just needs to look at Nadal and they crack up. What’s so surprising about it is that Federer has a reputation for being head-boy sensible; here, he’s the daftest kid in the class.

He says Nadal has been one of his great friends on the circuit, along with his Swiss compatriot Stan Wawrinka. Who else makes him laugh? “Andy Murray is very funny. I like chatting with him. Gael Monfils is good fun, he’s always chilled out. There’s not one guy I don’t get along with, which makes the tour so much more enjoyable. At the start of your career, yes, you can be tough, focused, a warrior on the court, but we get away from it and have a nice time. That’s why I think we see players hanging around longer. Before, everyone was so serious and like, ‘I hate that guy.’ Is it nice when 50 players don’t like you? I think they needed it to get jacked up.” What period does he mean? “The 70s, 80s and 90s. Today we’re still tough on court, but we don’t hold a grudge.”

There is one thing he thinks has changed for the worse – the grunting. There is a good reason why he doesn’t grunt: it puts him off. “Back in the day, people didn’t grunt so much,” he says, “but now everyone does. I always thought, if I do that, my mind is with the grunting rather than the shot. I’m OK with it to a certain level, but I don’t like it if it’s too loud or it’s used in key moments. That becomes unsportsmanlike.”

Another between-the-legs shot, at Wimbledon 2015. Photograph: Getty

Tics seem more pronounced in tennis than any other sport. Does he have any? “Not really.” Which of his rivals’ are the worst? “Rafa’s are somewhat obvious,” he says. Before every serve, Nadal pulls an imaginary wedgie out of his bottom. “I think it’s worse on TV than actually playing him. When he’s about to serve, you’re focused on yourself, not what he’s doing with his hand.” Does he get annoyed when players’ tics slow the game down? “I get frustrated with umpires allowing them to go over the time limit. I don’t want us to lose viewers because we’re playing two points every two minutes, or you hit a let call and go through the whole routine again. There’s a danger of that.”

We meet the week before Maria Sharapova is given a two-year suspension for taking the banned drug meldonium. Federer believes there has to be a zero-tolerance approach to banned substances. “It doesn’t matter if you did it on purpose or didn’t know about it, you have to be thrown into the same basket. You’re not allowed to do it. You need to be sure about what goes into your body.”

Commentators have suggested tennis might be having its own Lance Armstrong moment. “I think that’s an exaggeration, but we have to do more testing. My Olympic federation, Switzerland, is quite aggressive, but I know others are not. Every time we are in a quarter-final we should be tested because that’s when the prize money starts going up, and players should know – once you make a mini breakthrough, you’re going to be tested. I also believe in storing blood and maybe urine samples for 10 years – that would scare a lot of players.” And he would impose retrospective bans? “Yes. We’re always playing catch-up, so scare them by saying, ‘You can do whatever you want today, but just know that, down the road, we’ll come back for you.’”

Tennis has also suffered a recent match-fixing scandal: in March, Italian prosecutor Roberto Di Martino said that more than two dozen top players should be investigated for links to betting rings. Federer says he has never been approached, but first heard of the problem eight years ago: “We had somebody come in to a player meeting and explain the whole problem, and I was like, ‘What is he talking about?’ and then, ‘My God!’ Hopefully we can get rid of it; but it’s scary it’s in the game. And tennis is a one-man thing. One guy can decide what he’s going to do, unlike in other sports.”

I have never met a sportsman so relaxed in his skin, so utterly without side or suspicion. The only times Federer becomes defensive are when I suggest Nadal is in decline (“Well, he’s not struggling so much. He’s top five in the world again”) and that Murray might benefit from his sartorial advice (“Well, that’s your opinion!”).

With US Vogue editor and good friend Anna Wintour. Photograph: Rex

Ask a question – any question – and he answers fully. So I go through a quick Q&A from fans. What happened to Juliette, the cow presented to him by the organisers of the Swiss Open in 2003? “The cow had a baby and that cow had another baby, and now the first two cows are gone. They are eaten. That’s how it goes.” Who would win in an arm-wrestle between him and Nadal? “Not me. My coaches don’t allow it, they think it’s not good for my arm. I have tried and I’m very weak.” What language do you keep score in? “Swiss, German or English, depending on where I am.” Does he really hang out with US Vogue editor Anna Wintour? “Yes, we keep in touch.” How good a mate is she? “Good friend. She is unbelievably supportive. The first time I met her, I didn’t know who she was. She’s super close with my wife.” Does she give you fashion tips? “Sure. I ask her what does she think about this, and she’ll say, oh, this is terrible or this is great.” What did she think was terrible? “She didn’t like it when I had a snake print on the back of my shirt. When I sweated, it opened up for ventilation – it was a good idea from Nike, but she just said, ‘I don’t like it.’” (He has collaborated again with the brand on his new range.) What’s the flashest thing he’s bought? “Cars and watches. I have six cars.” What kind of dad is he? “Loving. I can’t cuddle my kids enough.”

***

In his New York Times essay, David Foster Wallace wrote that Federer was “both flesh and not”. In a New Yorker profile, Nick Paumgarten developed the theme: “The point is that to root for Federer is to root for a Platonic ideal,” he wrote. “It is like rooting for truth.” I ask Federer if he has read the essays and books he has inspired. He looks embarrassed. “I don’t like it so much.” He recalls meeting Foster Wallace. “The interview was very odd. I didn’t know whether it was going to be a genius piece or the worst piece of all time. When it came out it was like, oh my God, I never thought this was the direction he was going to take. It made big waves. People thought it was a great piece.”

And what does he think? “I think he found a way of saying it, this religious experience, in a way some people could relate to. But in sport, everything is a superlative.” Did he think, I’m good but not this good? “Exactly. I get uncomfortable with that stuff.”

Jacket, £215, from the NikeLab Presents NikeCourt x Roger Federer: ‘Unlimited Class’ collection. Styling: Martina Russi. Grooming: Julia Ritter. Photograph: Mathias Braschler and Monika Fischer/The Guardian

It’s four years since Federer last won a grand slam. Unsurprisingly, there are endless rumours about his impending retirement, but he insists he has no plans. “I don’t want to say I’m enjoying it more, but it’s different. I have a deeper love for the game today. Before it was chasing the dream. Today it is living the dream and appreciating I can still do it. It’s a wonderful feeling.” And he still feels capable of winning. “Is Djokovic now the man to beat? Absolutely. Does he deserve to be where he is? 100 per cent. But is he beatable? Yes, of course he is. I beat him last year three times.”

So many fans thought that, as soon as he stopped bossing the game, he would just walk away. “Yes,” he says, “I’ve heard retirement [talk]since 2009 when I won the French Open and people were like, well, what else are you playing for? I’m like, what’s wrong with you people? Don’t you understand that playing tennis is great fun? I don’t need to win three slams a year to be content. If the body doesn’t want to do it, if the mind doesn’t want to do it, if my wife doesn’t want me to do it, if my kids don’t like it, I’ll stop tomorrow. Zero problem. But I love tennis in such a big way that I don’t care if I don’t win so much any more. For me that is irrelevant.”

If there’s one tournament he’d like to win again, what would it be? “Wimbledon,” he says instantly. “This is where my heroes – Becker, Edberg, Sampras – won, I won the juniors there in 1998, my first slam, I won all these unbelievable matches there. Wimbledon is the holy grail.”

• The NikeLab presents NikeCourt x Roger Federer: ‘Unlimited Class’ collection is available at nike.com/nikelab from 23 June. Wimbledon starts on 27 June.