Steve Hansen and Joe Schmidt are wily men well versed in the wasteful avenues of getting sidetracked and the great chance this match offers for another check on their World Cup progress.
Nothing's ever quite a level playing field in rugby. with the All Blacks at the end of a long season, and the Irish starting their campaign, but this rare chance for heavyweight competition is bullion for the players and coaches.
Best against the best, top two teams in the world, pressure like they have not faced for some time - this game is a nest-egg for everyone. The Irish will claim the financial windfall and their spectators will crave justice for the last-play defeat in 2013 which continued the home hoodoo. That has pushed out to a 113-year stretch but the work Schmidt has done with his squad claimed that famous win in Chicago and has kept the group improving their world ranking.
They are very organised, usually disciplined, although extremely wary of tomorrow's referee Wayne Barnes, they have honed a style which suits their skills and temperament, and along those paths, they have gathered confidence in their ability and methods. Is it enough, though?
Do Ireland really believe they can win, and in the other dressing shed, do the All Blacks think they have enough sting left for a strong response?
Both will talk about getting a result if they play well, and while the All Blacks are not at their best, the suspicion is they will have more belief than Ireland and will find a way to get the job done. They have a wider range of methods to find a result, but getting those to click has been an issue.
Hansen has poured his trust into a starting group with one injury change, as 2013 match-clincher Ryan Crotty comes into the midfield for the injured Sonny Bill Williams. In tough conditions against England, they struggled as much with themselves as the lumps in white, and that uncertainty has appeared more often this season. Rivals have all upped their games and created extra heat, while the All Blacks have stuttered.
When they release the shackles, like Beauden Barrett's scrum move try against the Wallabies in Yokohama, no team can match them, and a few strikes like that and more of Brodie Retallick's muscular ballet can fend off the Irish ambition once again.