In Joe we must trust. Ireland coach Joe Schmidt has taken the side of caution over chance for the first of two shots at putting a bullet in the New Zealand hoodoo on Soldier Field tomorrow.
In just about every decision open to Schmidt, experience has trumped exuberance and even the compelling evidence of form.
The reluctance to hand the number 13 shirt to Garry Ringrose for his debut has allowed Rob Kearney to keep his place.
The Louth man has been a part of the Irish furniture, when fit, until a number of hamstring strains ruined last season.
The 30 year-old will win his 70th cap for Ireland not on form, but on the trust built up between player and coach.
Kearney's mastery of the basics of the full-back position has earned the confidence of Schmidt.
But, he has not finished out one match this season, playing six times for a grand total of 378 minutes.
He has looked well short of what he can be at his best.
In contrast, Ringrose has matured with every minute for Leinster, met every challenge head-on to start and finish all seven of his matches.
There has been resounding cheer about how the 21 year-old has embraced the physicality of Castres and, especially, Montpellier in The Champions Cup.
The decision to hold back Joey Carbery, just turned 21, is much more understandable.
Ireland need the expertise of Jonathan Sexton to guide the game in the right direction.
When Paddy Jackson 'vacated his seat on the plane', the New Zealand-born fly-half had to be included.
This does not detract from his talent. It just shows Schmidt knows what he has and he wants to treat Carbery with care.
"There were a number of variables involved in that, including the balance of what was coming off the bench and what we had starting," said Schmidt.
"We have tried to go with a little bit of experience, just because of the magnitude of the game and the quality of the opposition.
"Once those younger guys do get on, it will give us an opportunity to assess them a little bit against a very, very high standard of opposition."
This decision smacks of common sense with one eye on keeping the game close and another, maybe, on what might happen back in Dublin two weeks later.
Above all else, Schmidt will have the best long-term interests of Ringrose and Carbery upper-most in his mind.
The prospect of throwing them in against what many observers rate as the best team in the history of the game would be based on suspicion rather than fact.
Schmidt has taken the view this is not the time or the place for guesswork, although the coach does seem committed to giving them their heads at some point.
"It's a little bit daunting for them, but it's a great opportunity for them to learn," said Schmidt. "It's not ideal. It's a bit of a baptism of fire.
"But, they are both quite natural players and have shown great enthusiasm for what's ahead."
Either way, Jared Payne will have to switch from full-back at Ulster to outside centre for Ireland and absorb all that entails against the most rapidly moving backline in the world.
This will be a litmus test for tight-head Tadhg Furlong as the Wexford man looks to build on the firm foundation of a summer in South Africa.
A natural footballer for such a large man, Furlong has to consistently lock down the right-hand side of the scrum first and foremost.
Once this can be achieved, the sky is, literally, the limit.
The 23 year-old's mobility, sound defence and superior skills can become an undercover weapon for Ireland.
When Peter O'Mahony was deemed unable to make the flight, Jordi Murphy was nailed-on for the number seven short for his lineout agility alone.
The time to decide between Jamie Heaslip and CJ Stander for number eight will not arise until O'Mahony and Seán O'Brien are back to their best.
Ireland: R Kearney; A Trimble, J Payne, R Henshaw, S Zebo; J Sexton, C Murray; J McGrath, R Best (capt), T Furlong, D Toner, D Ryan, CJ Stander, J Murphy, J Heaslip.
Replacements: S Cronin, C Healy, F Bealham, U Dillane, J van der Flier; K Marmion, J Carbery, G Ringrose.