As a player and a coach, Mains spanned the epochs of the classic All Black, Colin "Pine Tree" Meads and Jonah Lomu, the Tongan-blooded giant who was supposed to revolutionise the game with an unprecedented combination of speed and power. It means that Mains has a background of impeccable authority in his current role as the moral guardian of both New Zealand's and the world's rugby.
Last week he blowtorched Woodward's Lions after the first-Test débâcle in Christchurch, saying they were quite the worst wearers of the proud red shirt ever to set foot in the land of the Long White Cloud - and, if that wasn't bad enough, also crippled by Woodward's poor selections and lack of traditional Test-match preparation.
Before this morning's re-match he was giving Woodward's New Zealand opposite number and his own successor, Graham Henry - who in the eyes of most of his countrymen has been walking on that white cloud ever since last Saturday - some of the treatment.
Mains thought the decision to stand down Justin Marshall, arguably the most influential player in the first Test, was "astonishing and worrying" - though perhaps not enough so to imagine the Lions whistling their way out of the graveyard.
However, spending a little time with the Last of the Mohicans - so called because he chose to walk into the mists rather than compromise his belief that a coach must always impose his vision of a team and not give a damn for player power - does not resolve one of the greatest mysteries in all of sport. It is a puzzle that intensifies in direct proportion to the length of your exposure to the extraordinary culture of New Zealand rugby. In Wales the game is an optional passion. In South Africa it is a way of measuring your worth against every other branch of humanity. In New Zealand it is the breath of life.
So how come the All Blacks have gone nearly 20 years without adding a World Cup to their first one in 1987?
"I wish there was one clear way of answering that," says Mains, "but you know team sport is a lot about cycles, developing teams and talent and sometimes that cannot be made to order. I guess I have reason to know that as well as anyone."
Mains managed to say that without exposing the abrasions to his soul, but of course no one ever came closer to winning any form of a World Cup than Mains in Ellis Park, Johannesburg, in 1995. The All Black out-half Andrew Mehrtens missed with a dropped kick on the stroke of full-time; South Africa's Joel Stransky landed one with just two minutes of extra time to go. There was also a problem of food poisoning which some here still swear was a work of sabotage, a suspicion not slackened by the arrogance of the victory speech of the president of South African rugby, Louis Luyt, who said that it just proved that his nation would have mopped up the honours relentlessly but for the boycott of the apartheid years. That left New Zealand in a paroxysm of rage that a decade on can still produce some disturbing after-shocks.
Something else you cannot make to order is undying fidelity to the old ways of All Black rugby. When Mains, an Otago full-back, broke into the New Zealand team, it was still locked into the ethos of Meads, the legendary lock who once played with a broken arm wrapped in a leather sheath. In a Test against South Africa, the big man from King Country performed a piece of skulduggery that provoked an ill-considered attack by the inexperienced Springbok centre John Gainsford.
Gainsford chased after Meads, jumped on top of him and threw some punches. Many years later the incident was still capable of chilling Gainsford's blood. He recalled: "He grabbed hold of both my wrists. It was like being held by a band of steel. I couldn't move. He looked up and said, 'Don't bother, son. Now you know what international rugby is all about'." The Irish scrum-half Andy Mulligan paid the ultimate tribute when he asked: "What does the best forward in the world mean? Is it applicable to anyone? The answer to both is probably Colin Meads."
That was the All Black mystique that Mains entered when he joined the team in the epic, lost series against the Lions in 1971, taking over from the hugely respected Fergie McCormack after he had been cut to ribbons by the tactical kicking of Barry John.
Mains returned to Otago a few years ago with all of his old priorities in place: players might be earning big money, they might see themselves as celebrities in the way that the Pine Tree never did, but it didn't remove the need to slave beneath the demands of being an All Black. Professionalism didn't mean that playing rugby in New Zealand ceased to be a sacred chore. But the players rose up and drove away Mains. They said that his belief that it was still a case of "the coach's way or the highway" could no longer be enforced. The rebellion was led by the high-profile All Black hooker Anton Oliver.
Mains retreated to Otago, but it would be wrong to assume that it signalled for him the end of All Black possibilities as the defining force in world rugby. He thought New Zealand should have won the last World Cup, Woodward's great prize, and that in Carlos Spencer they had a much more imaginative out-half than the fabled Jonny Wilkinson. He felt that the line between success and failure was as fine as his own team's in Johannesburg.
He says: "Just before the kick-off of the quarter-final game in 2003 I turned to my wife - who is South African - and said, 'I'm afraid your boys are going to have a hard time. I've rarely seen a New Zealand team so focused'. But a week later I was not so sure when they ran out against Australia. The Australians hadn't been doing much, but they looked right ... we didn't. Even so, there was hardly any difference between the teams ... in the space of a minute we missed a certain try and Stirling Mortlock made the interception off Spencer. That was the momentum, that was the game. In 1991 we caught an Australian team on the rise, when we were just going down, and in 1999 only the French could have beaten us in the way they did.
"Now I think we do have a World Cup-winning team for 2007 in France. If we don't get complacent, if the likes of Richie McCaw and Daniel Carter develop as they should, this is a fine collection of players. A lot changes in life, but some things don't. There is only one way to build a team. You have to give it focus and proper development. I didn't like the Marshall decision this week because it smacked of a little complacency. I hope I'm wrong, but if you have a team that has just run the opposition off the park, I don't think you leave out the man who was most influential. At out-half Daniel Carter is a wonderful young player - maybe one of the best of all time - but against the Lions last week he was all the better for the balance and judgement of Marshall. I don't think you discard something like that so easily. No, you shouldn't be that confident."
The year after Mains came so close to winning the World Cup, his team went back to South Africa and rammed the hubris of Louis Luyt back down his throat. But Mains was no longer around. He loved the poise and the vision and the power of his protégés Mehrtens, Glen Osborne and Jeff Wilson, Josh Kronfeld. He warmed to the immensity of Lomu, who over-ran England so monstrously in Cape Town in the semi-final, and watching the great No 8 Zinzan Brooke was to see both artistry and cold steel. Lomu still says that Mains' singular vision was the most inspiring influence of his career. But Mains couldn't go on. "I had four years of running the All Blacks and I felt I had gone to my limit," he says. "There is so much involved, so much intensity and demand."
So he put down one of the greatest burdens in world sport. However, like about four million other New Zealanders, he would never dream of ending the search for the holy grail.Reuse content