It used to be that a test in Dublin was mostly a social week for the All Blacks. One where they could enjoy the legendary craic and then pop down to Lansdowne Road on the Saturday afternoon for what would be a regulation 20-point win followed by a properglug of Guinness.
Dublin was about the perfect touring venue: fun, lively, welcoming and the rugby hard enough without being overly taxing.
But that's all changed. Ireland have been world rugby's biggest improver in the last decade, ditching some of their old amateur habits to get themselves fitter, more disciplined, organised and cohesive to become a consistent threat.
The old Ireland could occasionally scare the All Blacks: run them about for 60 minutes or so before the emotion waned and passes that were sticking suddenly weren't and the black machine would smash over the top of them.
But the old Ireland could never beat the All Blacks. In 111 years they never once managed it until an unseasonably warm, late Autumn day in Chicago altered the path of history.
Ireland, after coming desperately close in 2012 and 2013 to famous victories, finally found the resolve in November 2016 to stick to their plan for the full 80 minutes and do what many thought they would never manage and beat the All Blacks.
What that victory did was give Ireland the self-belief they had been missing. It enabled their players and coaching staff to see that the All Blacks were not the mythical beast that couldn't be slayed.
That defeat effectively humanised the All Blacks players in the eyes of their Irish peers and two years later, they had their next victory.
And if we look at the last five tests between these two, the All Blacks lead 3-2 but with the exception of the World Cup quarter-final in 2019, the games could have swung either way.
In 2013 the All Blacks produced the greatest passage of pressure rugby ever seen to conjure a try long after the hooter to sneak home 24-22. While Ireland won in Chicago, the All Blacks had clawed their way back from being 30-8 down after 45 minutes to trail just 33-29 with 15 minutes left.
On another day, they would have ridden that momentum to get in front and stay in front.
When the two sides met in Dublin two weeks after they had played in the USA, the All Blacks eased to a 21-9 win, but were lucky that Malakai Fekitoa had not been red carded for a high tackle with 30 minutes to go and their lead at 14-9.
Lucky because the judiciary hearing after the game found that the tackle had met the threshold for red.
The last time they met in Dublin, three years ago, was a genuinely epic encounter where the intensity of the game never relented and Ireland produced the one decisive attacking play which enabled them to score the only try of the test.
A trip to Dublin these days for the All Blacks is not the same by any means as Ireland have become a genuine rival. The All Blacks are careful to speak respectfully about all their opposition, but you know with Ireland, they really mean it now.
And that's why this weekend's test will have such a major bearing on how the 2021 season ends up being viewed. It has been a long season for the All Blacks and although they have played 13 tests, they haven't faced too many truly searching examinations of their character.
The two tests against South Africa were proper heavyweight clashes and while Australia are a better side than many give them credit for, they play a ruck and run style that didn't necessarily stress the All Blacks known points of vulnerability.
Ireland play a low risk game. They kick well, chase well, defend well and storm the breakdown and that's why securing a win at Aviva Stadium has become as hard as winning at Twickenham, Ellis Park or Suncorp Stadium.
Ireland, to some degree could be described as South Africa Lite and while that may be misrepresenting their growing ability to play expansively, it does fairly reflect that the general tone of their rugby is conservative and that they will broadly ask of the All Blacks many of the same questions that the Springboks did.
The clash in Dublin is the first real opportunity for the All Blacks to see just how much they learned in their series against South Africa and how well they can impose themselves against supremely physical teams that don't want to let them play.
A test in Ireland doesn't afford the same social opportunities as it perhaps used to for the All Blacks but they can be assured at least that unlike the old days, that they will have earned themselves a little celebration should they win.