I learned a lot about scrum-half play from George Gregan and Fourie du Preez, but then the best coaches are often the best players. If you ask the right questions, you will get a lot of good answers.

Australia and South Africa play a similar way in that both countries value their 9 and 10 equally, whereas New Zealand tends to play through their 10 and France has always loved its 9. But that doesn’t mean that Australian 9’s play the same way as South African 9’s. In many ways Gregan and du Preez were completely different players.

George, like Will Genia does now, preferred to manipulate the defence. He would often move backwards or laterally in order to try to pull the first defender at the ruck onto him, then he would slip a guy back in on the inside. He was a very different player to Justin Marshall or Mike Phillips, big men who like to take on defenders directly.

Fourie is slightly different again. He particularly liked to attack the outside shoulder of the second defender, a move that set up a couple of forward runners to hit the space. But he was also strong enough to pick and go at the first defender or he would set up Butch James on the outside.

The approaches to defence are different again. The Australian and New Zealand 9 tends to sit in behind the ruck as the second defender, looking to fill any space that might appear. It also keeps them close to potential turnover ball.

Du Preez played much deeper. He caught more kicks than Percy Montgomerie, South Africa’s full back at the 2007 World Cup. He would defend one touch line and a wing or full back would take the other side. But then Fourie was such a superb kicker of the ball that South Africa wanted to give him the opportunity as much as possible.

Most teams will have a philosophy about how they might want to play. French scrum-halves are usually proficient kickers. Australian scrum-halves tend to be great ball players. New Zealanders have had a lot of strong men, South African scrum-halves have sometimes seemed like an extension of the pack.

But whatever type of 9 you have, the player and the coach have to understand his game.