Ireland, perhaps more than any other nation, have been the beneficiaries of New Zealand's intellectual rugby property seepage.
In the last decade they have built a team that is unquestionably Irish in mindset and vision, but it's one that has more than a hint of Kiwi flavour to it.
There will be three men wearing green – James Lowe, Jamison Gibson-Park and Bundee Aki – who were manufactured in New Zealand but assembled in Ireland, and a fourth in Joey Carberry whose formative years were spent in the winterless charms of Dargaville.
All four are thunderously proud to be playing for Ireland, but the way they see the game, the instincts they have honed and the skills they have developed are mostly a product of New Zealand's system and not Ireland's, and that is partly why the Irish have become such a powerful force on the world stage.
Ireland used to sit in the freezer as a vibrant green, now they have enough black swirls to be rebranded as Kiwi Ripple and are a different proposition to their plain old former selves.
The Irish haven't conducted Viking raids to these shores to pillage what they can, but they have cleverly picked off a few waifs and strays, rummaged around in the bargain bucket and turned the likes of Aki, Lowe and Gibson-Park into world-class test players.
And for the better part of the last 10 years, they were guided by New Zealander Joe Schmidt who injected a steeliness and discipline which gave Ireland a greater sense of belief and purpose.
The upshot of this Kiwification programme has been to transform Ireland into one of the game's genuine heavyweights and in the process, intensify their rivalry with the All Blacks.
It's a rivalry that is built on mutual respect, but so too has it been spiced by the presence of familiar faces in the Irish camp.
The All Blacks so regularly encounter former teammates in other test sides – men with whom they were once in the Super Rugby trenches chasing the black jersey dream – that it's natural to assume it barely registers now.
But despite it being such a common occurrence, the dynamic remains strange and challenging.
Ireland's Kiwi-born stars Jamison Gibson-Park and James Lowe. Photo / Getty
The emotions that arise in confronting other New Zealanders on the international stage are often pronounced and complex for those representing the All Blacks to process.
Test football brings an intensity of emotion as it is, but when a few of the blokes on the other side were once close friends, popping round for barbecues with their families, it's a yet more confronting and confusing business to understand.
Friends become enemies and while players are genuinely happy to see their former teammates succeed on the international stage even if it is not in a New Zealand jersey, they also feel a sense of betrayal about that at the same time.
And there is no doubt that one of those toughest days came last year in Dublin, where Gibson-Park and Lowe were so instrumental in Ireland's 29-20 victory.
Lowe had the game of his life last year, scoring Ireland's first try, but more significantly, he produced a match-winning tackle with 10 minutes left where he was able to dominate Rieko Ioane to create a critical turnover penalty.
It was a big moment as Lowe, in 2015, had been on the verge of All Blacks selection, but it never came mostly because there were concerns about the robustness of his defence.
Those moments carry a particularly deep pain when they are inflicted by someone who the Kiwi system rejected or couldn't find room for.
It was Gibson-Park, however, who inflicted the greatest damage in Dublin last year. Ireland, under Schmidt, had built a highly effective but relatively limited game plan, much of it focused on the box kicking expertise of veteran halfback Conor Murray.
But new coach Andy Farrell arrived in 2020 with a plan to add more flair and width to the vision and to play at greater pace.
So he dropped Murray and picked Gibson-Park, a man who had been something of a Super Rugby nomad in New Zealand, drifting from the Blues to Hurricanes without alerting anyone to his true potential.
Akira Ioane and Jamison Gibson-Park hongi after Ireland's victory over the All Blacks last year. Photo / Photosport
There he was, though, against the All Blacks, dictating everything. Ireland played at a pace that surprised the visitors and Gibson-Park ran the show, passing here, running there and pulling the All Blacks horribly out of shape at times.
It was a performance that greatly impressed Aaron Smith who was watching from the stands as he'd only just joined the squad after the birth of his second child.
But as much as he admired it, he hated it as it was Gibson-Park's decision-making, speed and accuracy that made Ireland so hard to contain and shut down that day.
And it was a performance that the All Blacks have analysed at length this week and as Smith revealed, a big part of their plan at Eden Park will be making sure Gibson-Park is not the most influential number nine on the field.
"I had some good battles with Jamison – great player and he's a good man, too," says Smith.
"The way he's number one in Ireland at halfback now is pretty impressive. He's forged out an awesome career with Leinster and now he's transferring it to test level and he's a big part of our plans this weekend, trying to make sure he has a slower night than how he likes to play.
"I was in the stands last year, hopefully he is not going to have as nice a ride as last time."
The inference is clear – losing hurt the All Blacks, but seeing a couple of well-known characters play such a major role in the defeat, meant the loss resonated more deeply and is one that has not been forgotten.
"There is obviously still scar tissue," says Smith. "You would be silly not to think about last year."
