IT is not what you think.

It is not that obvious. A tennis ball has other uses than to be hit by a racket. A Scot can give it the Glasgow kiss or apply the boot. The result is head tennis, the game that regularly ends a Murray training session on court. This sort of Murrayball also speaks to the concept of marginal gains and how they can come in large sizes. Head tennis is Team Murray at play but there is a seriousness of purpose behind the game and an undeniable importance in the figures scrambling to flick a bouncing tennis ball over the net.

Murray learned quickly that he could not win alone. His team has been formed to provide him with help, reassurance and expertise. It also strips Murray of the ability to blame a lack of outside resources. "Everybody has to be in the right place. Then I have no excuses. No cop out," he told me in 2009 in a chic Paris hotel.

The core of the gang has been constant. They are the subject of jocular, schoolboy badinage. There is Jez Green, the fitness conditioner; Matt Little, who also works on fitness; Andy Ireland, the physio, and Dani Vallverdu, the 25-year-old Venezuelan, who has become Murray's coach on the road. The influence of all four is important, but Murray remains the boss.

It is something that he has had to learn to accept and the lessons have not been easy. While the backroom staff have remained unchanged, coaches have been fired with the regularity of the one o'clock gun at Edinburgh Castle. Mark Petchey, Brad Gilbert, Louis Cayer and Miles Maclagan have all coached Murray and been moved on.

By the age of 22, Murray had undergone the difficult process of telling Gilbert, a successful coach to Andre Agassi, that the partnership was over. Murray told me then that the decisions to dispense with Petchey and Gilbert had tested his resolve but were a part of the process of becoming the best.

"I have learned to take responsibility for everything I do," he said. "When I was young I did not quite know what I wanted and that is where I have really grown up. I have learned what I like and what I need. I have made a lot of tough decisions. I had to. I did it because it was the best for my career."

He added: "When I stopped working with Mark Petchey, I was 19. You are telling a 35-year-old, well not firing them, but telling them you need to do something different, you need to work with someone else. That is a tough thing to do. It doesn't happen in any other area of life. A 19-year-old at university or high school or whatever, he is not telling somebody that the job is not getting done properly. It is tough, it is quite an intimidating thing to do. That time was very difficult.

"I don't like doing it but it is something I understand I have to do. I must do what is best for my career. You have to tell people, 'I am sorry, this is not a personal thing but I need to make a change'. You have to do that.

"You have to grow up quickly. It is one of the differences between an individual sport and a team sport. You are not controlled by something or by others, you have to control yourself. It is so important to go on the court and feel totally responsible for your performances. If you are going to blame other people, you can't focus on the match properly. It is such a short career, maybe eight or 10 years at the top. You have to make the decisions. You have to."

If there is a pained emphasis in all of this, it is not just imagined. Murray is not confrontational. He lives with his team on the road and he has had good relationships with all his coaches, though there were strains with Gilbert. Yet the American and Murray can exchange genuine pleasantries when they meet on tour, where Gilbert is an idiosyncratic but sometimes compelling broadcaster.

The break with Cayer, though, was painful as he is a long-standing friend, but it serves as the prime example of the Scot's focus, some would say ruthlessness, in search of success. Murray, too, broke with his first agent, Patricio Apey, to make the move to Simon Fuller's XIX Entertainment.

However, the biggest change has been in the dynamic of the group. Murray is now more assured, more likely to eat on his own or with his long-time partner Kim Sears, if she is at a tournament, rather than with members of his team. The head tennis games go on, but the Scot is more likely to retreat into his own space afterwards.

Vallverdu, whom he met at the Sanchez-Casal Academy, is a close friend and has an input into training and practice. Murray, too, accepts professional advice from Green and Little on preparation and recovery. He has also been indebted to the work of Ireland, whose physio has allowed the player to take to the court while injured.

However, the close, almost intimate, talks are reserved for his meetings with his mother Judy and his coach, Ivan Lendl. Judy Murray has become almost a caricature in the press, but to depict her as some sort of pushy parent is to both misrepresent her and, perhaps more importantly for journalists, miss the story. Murray has slowly opened up in interviews but his most frank, insightful comment remains: "My mum's the one person who gets me, who understands me really well."

He is a champion, but a shy, introverted one. He is a grand slam winner, but he is a son. He has spoken of the loneliness of the court and it is understandable that he would look to a mother to counteract that but, more intriguingly, it is surely revealing that the two people he looks to for advice on how to play have impeccable, though differing, credentials.

His mother's influence on his tennis is incalculable since she has brought him on from a boy, turning him over to Leon Smith, now a rising star in the Lawn Tennis Association, when Andy was 11. Judy Murray was also instrumental in the development of, obviously, Jamie Murray, Jamie Baker and Colin Fleming. One could thus muster a Davis Cup team of Judy-trained players who would be the match for most sides in the world.

The theory of marginal gains has always been part of his mother's belief system. She has constantly looked at her son's game and sought out the best professionals in any area that demanded improvement. She has also served as a scout at grand slams, but the image of her as a ubiquitous presence at her son's side is simply wrong. But when she speaks, he listens. And when he speaks, she listens.

The result of one of these conversations, or more likely a series of them, was the appointment of Ivan Lendl. Within a year of his appointment, Murray had won an Olympic gold and a grand slam. This may be coincidence but it may be more instructive to reflect that the coach is the other person Murray listens to when discussing his game.

The marginal gains have been made across Murray's professional life, but his choice of coach is one of the most revealing. The Scot has improved under every coach from Petchey to Maclagan, but has never hesitated to make the next step, to say: "I need to work with someone else."

This process has been painful and it has involved Murray being without a full-time coach for a spell after the departure of Maclagan. Vallverdu stepped in, but another step had to be made.

Murray had shown strength and maturity in dispensing with coaches. Now he had to find both qualities in recruiting a coach that would test his mental resilience and his ability to take instruction. Murray had shown he was fit for change. It followed a long battle to be fit for the best.