There was a time in my coaching career at Northampton Saints when I wondered if our forwards had the required machismo. The French clubs had started to see us cheap cuts to be minced into sausage meat. Our scrum lacked respect. We weren’t strong enough and we weren’t hard enough.

I wanted to bring the Northampton forwards together, but I also wanted to see if anyone would break on the rack. So I went to head coach Wayne Smith and told him that I was taking away the pack to do 100 live scrums together. I had a counter in my hand and we were not going to come up short.

Two things I will stress are that we had a big enough squad at the time to do this and I made sure that the process was managed safely. There’s no point in a guy keeping going if he is injured. That’s not macho, that’s just stupid.

But I had my suspicions. There were a couple of young guys in key positions who talked it up all week, but were their mouths bigger than their hearts? A session like the one we were about to go through was bound to expose any weaknesses.

CRUNCH. The first scrum was a big hit. And on and on we went. Socks slipped down the legs and a few things were said, but as we crashed past the 50 mark the words got fewer. A waste of breath. The counter in my hand clicked past 80 and then there was a loud crack.

One of our props just quit. He stormed off. No backbone. Toys out of pram. The other forwards just watched him go, strong and silent while the broken man ranted on. He was shouting at everyone else, but he probably knew the next day that he was shouting at himself. His mates steeled up. He snapped. He never regained his credibility.

Some of our experienced internationals like Tom Smith just didn’t get it at the start. They began the process, because they were professionals, but you could see that they thought it was a crackpot idea. By the 100th scrum everyone knew what it was all about. They had come together. They walked back to the shed totally spent, but they were a team of men who had shed blood together.

Tom Smith was never the weak link. He was a hard man. At 108 kg Smith shouldn’t survive, but I remember Northampton going up against Agen, on a wet pitch, at a ground where the home side hadn’t lost for three years. On the morning of the game Smith’s back went into spasm.

He was in excruciating pain. He couldn’t walk. But Smith took some anti inflammatories. Some movement returned. Then he was able to jog. In the end he fronted against the Agen pack for the whole 80 minutes. Tough man.

A great scrummage needs eight men with that sort of courage. We have talked about the front row, but they can look silly if there is no power coming from behind. That is why Brad Thorn is held in the highest esteem by his teammates. He takes pride in his scrummaging.

Some locks just want to show off in the lineout and romp around the field in support. Isaac Ross is wonderful in the wide channels, but he is not known for his work in the dark places. Thorn puts it into every single scrum. He works on lifting heavy weights and squatting explosively in the gym. But he doesn’t leave it one the dance floor like some do. A prop had better have good technique if he has Thorn coming in behind him.

Thorn packs down behind Owen Franks for the Crusaders and the All Blacks because you usually put your most powerful scrummaging lock on the tighthead side. And the great scrums of the world, France, Argentina, Italy, have eight powerful scrummagers.

Sometimes loose forwards will come to you from a club coach who just wanted them to get out there and put pressure on the 10. Lazy. That’s just a part of their job. The loosies are incredibly important for a world class scrum. They have to support their mates. The set piece comes first. It’s a band of brothers.