How Ireland can prove they have learned lessons from last year's Six Nations loss in Wales
For the past 18 months throughout the rugby world, chaos theory has reined.
Coaches have preached the need for their players to be comfortable when the game throws surprises their way, to adapt to their surroundings and take control of their own destiny in the heat of battle.
They coach chaos, creating scenarios to take players out of their comfort zones in the hope that when the chips are down they will survive and thrive.
The lingo hasn't entered the lexicon in camp Ireland, but the theory appears to be there.
Joe Schmidt has talked about his players being able to adapt on the run, and in training he puts them through long drills of continuous play, introducing different scenarios in an attempt to get them ready for the unexpected.
Having done the preparation, they failed the test last season.
They haven't lost since, but the return fixture against Wales is the biggest test they have faced since and represents the best chance to show they have learned the lesson.
On a Friday night in Cardiff, the men in green were presented with a number of incidents that threw them off their stride and ultimately cost them a tilt at the title a week later.
They lost out-half Johnny Sexton to a Head Injury Assessment for eight minutes midway through the first half, while Conor Murray played on for 10 minutes either side of half-time after suffering an injury. While he was struggling, Sexton was sin-binned.
It was a crazy game, one Wales won 22-9 by outscoring their visitors three tries to nil, but only secured late on.
Had Robbie Henshaw not joined a maul in front of Rory Best before the captain touched down, Ireland might have led with 10 minutes remaining.
In the end, Sexton was charged down by Taulupe Faletau and Jamie Roberts pounced to secure the result.
Saturday provides an opportunity to show they have taken the experience and absorbed it.
Peter O'Mahony, who was a replacement that night, said yesterday: "We have to be better. It's 12 months on from the last Six Nations and you have to be improving.
"There are scenarios that might or might not happen, but we've got to be prepared. I think we are certainly better prepared and we have to be.
"We have to be if we're talking about beating teams like France and Italy, and coming up against Wales, we have to be better than 12 months ago."
In the intervening 11 months, Schmidt's side have beaten England, USA, Japan (twice), the Springboks, Fiji, Argentina, France and Italy.
They have been asked questions, but life has never been as uncomfortable as it was in the Cardiff cauldron.
In the intervening period, the reliance on Murray has eased thanks to Kieran Marmion's performances in his absence, but concern remains that a half-back injury could cause similar consternation.
This time, however, the concern lies on the out-half side where Joey Carbery is back-up for Sexton.
Undeniably talented, the 22-year-old is horribly short on game time.
It was widely expected that he would play for Leinster last weekend, but instead he trained with Ireland in Athlone and did not feature against Scarlets.
Instead, 21-year-old Ciaran Frawley made his provincial debut, coming on in the centre for Rory O'Loughlin after he went off with a head injury midway through the first half, before finishing the game at No.10 after Ross Byrne went off.
Indeed, the youngster even took over the kicking at half-time after Byrne had suffered a hip injury.
Since he wore the No.10 jersey for the first and only time this season when Ireland played Fiji in November, Carbery has played just 50 minutes - 20 at full-back for the province against Montpellier and 30 for his country at out-half.
He looked lively during his cameo against Italy, but the intercept pass he threw suggested rust.
This Saturday's game will see the intensity levels ratchet up, and if anything happens to Sexton there have to be doubts about the next man in line.
Few teams have made life as consistently uncomfortable for Schmidt's Ireland as Warren Gatland's Wales.
Although they won comfortably in 2014, the men in green have not tasted Six Nations victory in the fixture in three games since. Wales have developed a knack for disrupting Schmidt's powerplays and, although Ireland's attack has created openings, they have been unable to beat the defence.
Decisions have gone Wales' way on occasion, but Ireland are all about controlling what they can control.
There have been other occasions, particularly at home, when Ireland have been able to adapt on the run - most notably in November 2016 when they faced Australia for much of the game with Carbery at full-back and Marmion on the wing due to injuries.
A week after the Wales game, Jared Payne played on a half-empty tank and thrived as England were downed. Jamie Heaslip went down in the warm-up and O'Mahony stepped up at the 11th hour.
This week at the Aviva, the intensity levels will be ratcheted up to a level Ireland haven't seen since.
They can point to Paris as a moment of real growth. To work their way out of a corner in the way they did showed a combination of character, courage and the execution of their core skills under pressure.
Ireland are endeavouring to be one of the best teams in the world under Schmidt, one that can go to Japan as realistic World Cup contenders.
The squad is evolving quickly as Schmidt looks to get experience under the belts of a new generation of young players, and they are keeping the show on the road despite the changes thanks - in part - to an experienced core of players.
They have shown growth in plenty of departments over the past year, but the next six games will show a true measure of where they are.
They've engineered a position where they are two home wins from a Grand Slam decider in Twickenham, before they travel to Australia for a three-Test series.
Test matches like Saturday's will sense-check their progress.
If they are presented with cruel scenarios and can adapt, it will be a clear sign of progress from Cardiff. Chaos can come at any moment and Ireland must be ready.