HE stands feet splayed, racket gently swishing as if to banish imaginary horse flies at the former Gleneagles equestrian centre.

As coaches work dutifully, as youngsters rush to meet his every demand, Louis Cayer is master of all he surveys. The 63-year-old Canadian is part extraordinary motivator, part restorer of careers, part inspiration, part philosopher, all-encompassing tennis coach.

Cayer, a Canadian who arrived in Britain nine years ago, loves the island so much he has helped it win a Davis Cup and now seeks to help two of Caledonia’s most favoured sons achieve Olympic gold. He has been instrumental in bringing the doubles game in Britain to an extraordinary level but his brilliance as a coach ensures his presence in the Gleneagles Arena last weekend was beneficial to those whose tennis ambitions are humbler than contesting Davis Cup, Olympic Games or professional tours.

Cayer, in conjunction with Judy Murray and her Tennis on the Road initiative, held a masterclass for coaches, children and for guests at the hotel. For once the designation is not inflated. The Canadian is regarded as the greatest doubles coach in the world. He was integral to Britain’s success in the Davis Cup and Rio will be his fifth Olympics, with his cv gilded by the gold won by Canadians, Daniel Nestor and Sebastien Lareau, in Sydney in 2000. His efforts at Gleneagles, sponsored by Speirs Gumley, the property management company, were aimed at improving the quality of coaches in Scotland and at inspiring and nurturing the nation’s tennis hopefuls.

Cayer, watched by his four-year-old son, Sebastian, and his wife Stella, also a tennis coach, impressed on the students, whether coaches or players. his core values. This was done simply but resolutely. “I do not want to be interesting,” he tells me. “I want to be useful.” He is, of course, both.

Every player who has worked with him testifies to his dedication and his capacity for hard work. Cayer has to be sure his charges share that essential quality before he even talks about backhands or court positions.

“If I am a high performance coach, my first job is to develop a performer. They have to come with their focus on the court in every match. If they don’t have that I will not talk to them about tactics or technique. If they didn’t compete on court why should I tell them: ‘You didn’t do this or you didn’t do that’,” he says.

He adds: “If you have a great backhand and your head is not there or your heart is not there and you are not running down everything…then what is the point?”

He talks passionately about the need for “the head, the heart and the legs’’, saying this applies to all players, potential champions or those who are fated just to play at club level.

Cayer, though, is best known for his work with top players. His most spectacular success has been with Jamie Murray. Three years ago the young Scot was considering whether he had a future in the game. This week he could be ranked the greatest doubles player in the world.

Cayer told Murray three years ago that if he bought into the coach’s programme he could in 2015 qualify for the end of season finals and contest the finals of grand slams. This is precisely what happened, with Murray losing in two major finals before winning a grand slam in Melbourne in January. “If you say something will happen and it does, then that increases the player’s belief in you. It leads to trust, too, and that is higher than belief,” says Cayer.

The 30-year-old benefited hugely from the Cayer philosophy of how to cope, whether in the fast lane of world tennis or in life.

“This is about belief, attitude and values,” says the coach. “It can be summarised by saying to yourself: ‘Whatever happens I can handle it’. When you have that belief, then you cannot be stressed.”

There is a further twist to this philosophy and one that has been adopted enthusiastically by Murray. Cayer believes in not only instilling belief in his players but also encouraging them to plant doubt in the minds of their opponents.

“I tell players that they must be able to play their best at the end of matches. And they have to believe they will play their best at the end. Then they discover that they become stronger as their opponent perhaps is ‘choking’. Who is going to win?”

Murray’s game has also been refined to confound opponents. He uses chips, lobs, slices to unnerve his opponents, make them hesitate before making a definitive move. “Jamie, of course, plays well but he makes his opponents play badly. He destabilises people, he creates a level of uncertainty. You know in life that when you are uncertain you become anxious and when you are anxious your muscles tighten and them you play worse. Jamie does this to opponents.”

He adds: “He is also the best volleyer in the world. He has the full range. There may be guys who can hit it with more force but Jamie is the best because he can do it all.”

He says of the Australian Open doubles champion: “He had to start again in tennis. He should be very proud of himself.”

And what of Jamie’s brother who Cayer has worked with in the Davis Cup squad. “He always wants to improve. He always asks questions. And when he learns something. That is that. He doesn’t forget. He is a now complete doubles player,” says Cayer of Andy.

The brothers have won a Davis Cup together. Now they will go for Olympic gold. Cayer was in their corner at the final in Ghent. He will be there in Rio. It could be the best of doubles for the doubles maestro.