The making of Andy Murray

As Rafael Nadal was being crushed by Andy Murray here in the quarter-finals of the Australian Open earlier this week a thought might have crossed his mind: "Why didn't I keep my mouth shut?"

It was after the European Under-16 team championships in Andorra eight years ago, when Nadal's Spain beat Murray's Britain in the final, that a conversation between the two boys prompted a defining moment in the Scot's career. Nadal told a wide-eyed Murray about his life back in Majorca, where he trained in the sun and practised with Carlos Moya, one of the world's top players.

Murray had never had the chance to hit with Tim Henman and practised – when the Scottish weather relented or when he could play indoors – with his brother, Jamie, his mother, Judy, and a few county-level players.

When he returned home Murray told his mother: "Rafa's out in the sun all day. He hardly goes to school and he's playing four and a half hours a day. I'm playing four and a half hours a week. It's not enough."

From that moment onwards Murray knew that he had to move away from Dunblane if he was to realise his ambitions. Not even his brother's experience – at 12 Jamie had spent a miserable seven months at a Lawn Tennis Association academy in Cambridge – could deflect him from his course.

A trip to the Sanchez-Casal Academy in Barcelona with his mother confirmed his intentions. Murray played a match against Emilio Sanchez, a former top 10 player and one of the academy's founders, and beat him 6-3, 6-1. The whole atmosphere about the place was a total contrast to the training centres he had visited in Britain, where he felt most players were spoiled, lazy and lacking in ambition.

Within weeks 15-year-old Murray was back on a plane to Barcelona and practising regularly with players from the professional men's tour. Leaving home was not easy - despite the break-up of his parents' marriage when he was 10 he had enjoyed a happy childhood – but Murray revelled in the chance to develop his game alongside people who were as serious about his tennis as him. It was soon clear to the coaches in Barcelona that they had a major talent on their hands.

Murray may well have made it to the top without his time at Sanchez-Casal, but the experience taught him that tough decisions sometimes have to be made. He has never shied away from them. When he has felt he needed to take a new direction, he has sacked his coaches, despite any personal pain. When he had the rare chance to play for Britain in the Davis Cup's elite World Group in Argentina he withdrew from the squad – to the anger of his brother, who was also in the team – because he felt the switch to playing on clay might jeopardise his chances in upcoming hard-court tournaments.

Tennis can be a lonely business and Murray is luckier than most in that he has a mother who has spent much of her lifetime in the sport. When he needs to make hard choices, Mum's is the voice he listens to most.

Judy Murray won 64 junior and senior titles in Scottish tennis and made a brief attempt to play professionally before deciding that the life was not for her. The tennis world is full of pushy parents who drive their children forward, often with the aim of realising their own ambitions rather than their offspring's.

One of the reasons that Murray loves his sport is that he was never pressured into it. Judy ferried her boys to and from tournaments and practice sessions, but, like his father, Willie, never made them do things they did not want to. Andy once sent Judy a Christmas card in which he thanked her for "always believing in me, always supporting me, always letting me make my own decisions... but I most want to thank you for being the best Mum in the world."

Murray came from a sporting background – his grandfather played for Hibernian and a great-grandfather represented Northumberland at athletics, cricket and tennis – and from an early age loved games. He was a good footballer and at 13 was offered a place in one of Rangers' feeder academies, which he declined.

The tennis courts at Dunblane Sports Club were 200 yards from the family home. From an early age the Murray boys were regulars at the club. They were as close as brothers can be. Andy, who was originally considered the lesser talent, played his first tournament when he was five and at eight made his debut alongside the men in the Central District Tennis League. John Clark, an architect in his fifties and a much respected member of the Dunblane Sports Club, remembers his young doubles partner approaching him during a match. "You're standing a bit close to the net," Murray told him. "You should stand back a bit as you might get lobbed if I decide to serve and volley."

Growing up in Scotland's smallest city was a happy time, despite the horror that descended upon Dunblane Primary School on 13 March 1996. Andy and Jamie were at the school when 43-year-old Thomas Hamilton, who had run a boys' club there and knew the Murrays, walked into the gym and shot dead 16 children aged between five and six and a teacher before turning a gun on himself. Andy, who remembers being on the way to the gym when his class were shepherded into another room, recalls little about the day and, even now, does not like talking about it.

Judy was his first coach, but Leon Smith took over as Murray started making an impression on the junior circuit, culminating in victory in the 2004 US Open boys' event. Pato Alvarez was his coach at Sanchez-Casal, but there was a 52-year age gap and as Murray took his first professional steps he started working with Mark Petchey, a former player who was much younger and quickly formed a strong bond with the teenager.

Murray, nevertheless, knew within a year that it was time to move on. Brad Gilbert, who had worked with Agassi and Andy Roddick, succeeded Petchey as coach and took Murray to new heights. Brilliant at sizing up opponents, Gilbert also saw the need for Murray to build his physical strength and introduced him to fitness coaches and new training regimes. The relationship might have lasted longer had they clicked on a personal level, but the quietly-spoken Scot and the fast-talking American soon grew apart and within 18 months Murray was again looking for a new coach.

Having disliked the intensity of a one-on-one relationship, Murray now surrounds himself with a team. Miles Maclagan, a softly-spoken former British Davis Cup player, is his main coach, but he also works with Alex Corretja, a former French Open finalist. Two fitness trainers, Matt Little and Jez Green, and a physiotherapist, Andy Ireland, also accompany him on tour.

While Murray clearly has great respect for Maclagan, there is never a doubt as to who is the boss. Maclagan has his say on tactics and opponents, but knows that Murray has such an intuitive grasp of the game that he will always make the ultimate choices. As light relief Murray and his team have a system of forfeits – whoever loses at head tennis, for example, might have to go out to dinner wearing their clothes inside out – but the ringmaster rarely seems to have to pay the price.

Might the way he surrounds himself with his entourage be a sign of insecurity? When he is training at the National Tennis Centre back in Roehampton he is rarely seen taking lunch on his own or with anyone from outside his team.

Murray's dedication to his fitness work – as with all other areas of his preparation – is unerring. He has a hugely impressive physique and combines stamina and strength with speed and athleticism. Laura Robson, his mixed doubles partner at the recent Hopman Cup, asked Murray what he did in his free time and was in awe when he said that he spent some of it working on his fitness.

When interviewed on court earlier this week and asked to reveal something interesting about his life, Murray said he could not think of anything, which showed how boring he was. After he had beaten Nadal, an Italian journalist told him he looked so miserable that it was as if he had lost. "Have you ever sat in this seat before?" Murray asked. "I don't get excited about doing press conferences."

Murray's serious front – he is much less of an extrovert than his brother and admits he has a boring voice – may be a deliberate tactic to keep his private life private. "I enjoy my life," he said in a less public moment this week. "I have good fun off the court with the guys around me and I'm sure that 'boring' would be the last word to describe the days we spend together."

Nevertheless, he is not a party animal and can look uncomfortable in unfamiliar company. He likes having family around him – his mother and her partner are out here – and was in a long-term relationship with his girlfriend, Kim Sears, until they parted at the end of last year.

Murray always responds well to children and teenagers. Before a tournament in Dubai he answered questions from a hall full of schoolchildren who shrieked with delight when he said he loved playing on his Nintendo Wii. Within hours of 16-year-old Robson showing him her favourite computer game he was beating her best scores.

Only being the best will do for Murray – which is one of the reasons why he is on the verge of becoming Britain's first male Grand Slam singles winner for three-quarters of a century.