Secret behind the world's most successful team - how a country with just 4.8m people rule the rugby world
Ten months out from the 2019 Rugby World Cup, it's the question increasingly on the lips of rugby followers around the globe.
How on earth have New Zealand, a nation of just 4.8 million people tucked away in a far corner of the world, managed to conquer an entire sport?
How have New Zealand won back-to-back World Cups and completely dominated the sport in both hemispheres?
Their win ratio under coach Steve Hansen is around 90pc, a phenomenal achievement.
Even coaching legends of other sports like Alex Ferguson must doff their caps at such sustained levels of excellence.
As the All Blacks make final preparations for tonight's international against Ireland at the Aviva stadium, it is axiomatic that essential foundations underpin this formidable record.
It hasn't happened by accident, nor by some freak era in which a glut of world-class players just happened to arrive on the scene around the same time.
All New Zealand have achieved has been planned down to the last piece of minutiae.
Such is the intrigue of the question that I spent three years on a book that set out specifically to find the answers.
I lived in New Zealand for five months last year, travelling the length and breadth to elicit answers from people as diverse as current and ex-All Blacks, Maori and Pacific islanders, humble club officials, women in rugby, school teachers and even a former prime minister.
From the likes of New Zealand 'greats' like Brian Lochore, the late Colin Meads, ex-All Black coaches Graham Henry and John Hart, Beauden Barrett, Aaron Smith and Ryan Crotty, plus others around the world such as Willie John McBride, Tony Ward and Doug Howlett in Ireland, and Victor Matfield and Joel Stransky in South Africa, I garnered vital clues at every turn to explain New Zealand's supremacy.
In all, I interviewed more than 90 people worldwide.
What is more, given the fact that the book has been a No 1 bestseller in New Zealand and South Africa as well as No 2 on the Irish bestseller list, my eagerness to find answers to these questions seems to be shared by many other people.
What became clear time and again was that, at the heart of this supremacy, lies a ruthless efficiency fuelled by fear of failure.
Former Australian coach John Connolly put his finger firmly on the pulse of New Zealand's rugby men when he said, "all great teams in sport are ruthless in pursuing victory.
"You'll find it in any successful team in any sport. You need that obsessive personality and the Kiwis have got that."
And a fear of failure? Wing Doug Howlett put it best.
"I scored 49 tries in 62 Tests for the All Blacks (it is still a record).
"But there was not one time, one occasion when I felt completely sure of my place."
In no other country in the world or perhaps any other sport, would you find that.
But then, as ex-All Black lock Andy Haden said: "A fear of failure has always been there. It has always driven this system."
That fear overrides anything you must do for victory.
Haden once farcically threw himself out of a lineout against Wales in Cardiff in an attempt to win a crucial penalty.
Did he ever regret it afterwards, Willie John McBride asked him?
"No, never. In New Zealand, you are taught to do whatever it takes to win," was Haden's revealing riposte.
Haden also pinpointed what he called "the momentum kids get out of the environment in which they have grown up" as a critical factor.
"They are reminded constantly, every moment of the day, of the importance of playing well and winning.
"It is not just public pressure but words written in newspapers, it's the bloke at the gas station that says 'Play well on Saturday and win'."
An entire nation buys into these values.
Hand on heart, can any other nation make claim to inflicting such searing, sustained pressures on its young rugby men?
People might say 'Go well, enjoy the game.' But no way are they as obsessed about winning as New Zealanders.
These are a driven people when it comes to rugby union. The sport has the nation by the throat. Fathers, mothers, brothers, sisters, cousins, grandparents…the lot.
And most of them know more about the game and its intricacies than the average fan in a host of other countries.
It means that winning is not just an expectation, but an obligation.
South African World Cup-winning fly-half Stransky put it succinctly. "Rugby doesn't matter as much to the general population in other countries as it does in New Zealand.
"It is not the be-all and end-all in other countries that it is and always has been in New Zealand".
All over New Zealand, as I researched the book, the phrase 'The Jersey' was used constantly. It became an obvious title. But what does that jersey mean to young Kiwis?
I asked Australian Nick Farr-Jones if he thought the Wallaby gold jersey compared in importance to the All Blacks' jersey.
"Whether it can be said over the decades that we held the Aussie jersey in the same esteem as the All Blacks held their jersey, I very much doubt."
As the late Meads added: "I think it just matters more to the young men of New Zealand to wear this jersey than the young men of France or England to wear theirs. In England, rugby isn't even the number 1 sport."
But at times, this desperation for victory has spilled over into wanton acts of violence.
I explore this element closely in the book.
Even Meads, renowned as the hammer in the builder's bag, admitted to me in his last major interview before he died: "When I look back; yes, there were one or two things I regretted, felt I went too far."
Even the esteemed Graham Mourie, one of New Zealand rugby's greatest gentlemen, admitted he had lost respect for Meads when he saw him kick an opponent in the head.
The story is chronicled in the book.
As for the 'assault' on Brian O'Driscoll in the 2005 Lions tour, we should thank the gods his neck was not broken.
But every argument requires a balance. And, generally speaking, the scintillating rugby played by this exceptional team on so many occasions these days, provides a wondrous advertisement for the sport.
Likewise, their humility as young men stands out.
But then, those values are inculcated from above on their first association with the legendary All Blacks.
None of which is to say they are unbeatable. England could and perhaps should have sealed the deal last weekend.
Ireland could do so tonight at the Aviva - if they are mentally convinced they can.
But the intimidating thought confronting every foe is that New Zealand's supremacy, whichever the hemisphere, endures.
They do not win the odd game and assume bragging rights. They just keep on winning rugby matches, most especially the important ones.
And anyone wanting to match them, must build from their roots to achieve that. A sobering prospect.
'The Jersey: The Secrets Behind The World's Most Successful Team' by Peter Bills, published by Macmillan.