Thing is, you don’t have to be operating at Test level to have personal experience of this Irish phenomenon.

Leinster are masters of the art, too. Bulk suppliers to the national side, the Champions Cup holders can be a more flamboyant outfit at a level of rugby that is more amenable to such fripperies, but they are just as claustrophobic as Ireland when needs be.

Especially of late.

Leo Cullen’s side has scored 180 points in their last four PRO14 games, all played without their national contingent.

Only the Southern Kings have caused them problems and, coincidentally or not, managed some parity, in terms of possession and territory. Benetton, the Ospreys, and Dragons have all been squeezed-dry.

Go back to the European window, in October, and Leinster were claiming dibs on the ball and on the turf, as well.

Even in defeat, away to Toulouse. They had over 70% possession against Wasps and 74% territory in the round-one game at the RDS.

Like Ireland, they are adept at maintaining possession for minutes on end and will likely seek to do the same against Bath this Saturday.

A blink of an eye in everyday terms, that sort of time span can appear endless in the maelstrom of a professional rugby game.

“I don’t know if it’s the way (the game is) moving,” said Leinster attack coach, Felipe Contepomi. “Maybe it’s the way it suits some teams.

But, also, from our perspective, it’s not just about holding the ball until an opportunity unfolds. We try to create and detect opportunities.

“We’ve seen if, in the last game for us, we take the opportunities. It’s the way it is and when you have a team that attacks and attacks, you will have a lot of bodies in the front line and maybe the opportunities in the back line.

“It’s about moving and putting yourself in good shape, the shape we want to play, and when the opportunities appear, to take it. That’s the mentality, rather than just holding onto the ball, as opportunities won’t come. You have to create them.”

Leinster, like Ireland and the All Blacks, make this stuff look simple. It’s not. The number of things that can go wrong in three or four minutes of attacking pressure is infinitesimal — a knock-on here, a poor clearout there — and that’s before the opposition has its say.

Everyone needs to know their job, to understand their role in the organised chaos. Leinster training is unstructured, so as to replicate that, and it was put to Contepomi that there is something very Barcelona-like in the way they can hem teams in and dictate the play.

He digested that with a laugh. “Well, we have Messi, no? We have the best player (Jonathan Sexton) in the world. I don’t like comparisons. We are a team that is trying to get better and is trying to do what we do well even better.

“We still know we have a lot to improve on and a lot of areas where we can get better.

That’s where we are heading and trying to go to. Teams today, with technology, they scout you so much that they’d know exactly what you’re going to do, or try to know what you’re going to do. So, you have to be creative and try new things.

Leinster don’t dominate every game. No more than Ireland do. Munster limited their old rivals to one-third of possession and territory at the Aviva Stadium in early October. Connacht had the ball for over half of the sides’ meeting at the Sportsgrounds. But both still lost.

“Everyone speaks about Barcelona, because of the amount of points that you score. I would put it the other way round,” said Contepomi. “I would say that we’re very good because we defend very well. We don’t concede that many points. So, the day that we don’t score 40 points, we’ll probably be able to win a game because we don’t concede that many. While there are other teams that score a lot of points, but they concede 30 points and the day that you don’t score 31, then you lose the game.”

Points conceded this last four games? 51. Bath managed seven last week against Sale Sharks. Interesting.