If Japan set this World Cup on the road to success with that remarkable win over South Africa on the opening weekend, then my money is on Argentina to carry the baton through the knockout stages. They have already surprised some with the margin of victory over Ireland last Sunday, but what price an All Blacks v Argentina final?

If that happens and the Pumas beat Australia this weekend, is that so big a surprise? Probably to some in the northern hemisphere, because since 2007, the Pumas have been well under the radar of those not fascinated by Argentina and the rapid power changes in Test rugby.

Australia will not underestimate ‘dangerous’ Argentina, says Matt Giteau Read more

To understand Argentinian rugby and where it has come from, best go there and see from where this current batch of players have sprung. And if the chances are that they have middle-class backgrounds and come from the wealthier end of Argentinian society, then do not be lulled into a false sense of polite company.

Back in the ice age, when I was at Bristol and we had both Gus Pichot and Felipe Contepomi (then a young lad recommended by Pichot as “something for the future”) we toured Buenos Aires and, to be frank, were embarrassed to be out-scrummaged by a bunch of club players, none of them much bigger than 5ft 10in and then lectured at length on the techniques involved by a former fly-half, who turned out to be Contepomi’s dad. That is the kind of culture from which the current coach, Daniel Hourcade, has emerged, but his lack of big club or a Test rugby background clearly has not held Argentina back.

Before the Ireland game, Joe Schmidt was asked about the threats he saw within the Argentina team and name-checked just about everyone, front to back. However, he had particular worries about the back three. The word he used was “fear” and, as it transpired, he had every reason. Every time either Santiago Cordero, Joaquín Tuculet and Juan Imhoff got the ball, Ireland were in trouble. But why?

There are plenty from Sale, Grenoble, Bordeaux and, most recently, Cardiff Blues who would fail to recognise Tuculet as the try-scoring full-back at the Millennium Stadium on Sunday afternoon. Likewise the burgeoning Nicolás Sánchez at fly-half. This guy is so much better than the “medical joker” who went to Toulon last season, but I’m not sure while there whether he ever played alongside his current international midfield partner Juan Martín Hernández, possibly one of the great unfulfilled talents of world rugby.

OK, I know that Hernández has been playing Test rugby for a dozen years and has been at Stade, Natal, Racing Métro and then Toulon, but I’d argue that it is not until now, at the age of 33, that El Mago is playing the best rugby of his career and in the position most suited to his talents.

So, how can it be that Sánchez, Hernández plus guys I have worked with such as Leonardo Senatore and Gus Creevy, good professionals all of them, so clearly lift themselves into rugby’s stratosphere when wearing the pale blue and white? Well, as someone who first captained and then coached Pichot and had to get used to a smaller man screaming at me, I can believe in an enhanced “atmosphere” within the squad. But look a little closer and there is clearly something much more than passion.

I’m not sure who is Hourcade’s strategist – it could be him for all I know – among the eight-strong coaching panel, but he has clearly come up with something for the Australia defence coach to ponder. Initially I thought it might be a coincidence, but when Argentina score tries – and they have scored 26 in five games – a pattern is starting to appear.

Backs and forwards are not integrated in the manner of Australia, where it’s all-singing and all-dancing. Instead Sánchez and his scrum-half, either Martín Landajo or Tomás Cubelli, almost exclusively use the big ball-carriers to go up the middle at the embryonic stage of the attack. However, when the ball goes wide it’s at real pace and the surprise package is on the outside.

Argentina rugby interactive After using their big men to tie in defenders in the middle of the field, Argentina move the ball wide quickly. They often have two players hanging near the wing with decoy runners on the inside holding the drift defence and leaving the last defender with two players to handle.

Both Sánchez and Hernández have a good pass, as does Juan Martín Fernández Lobbe, but I’ll come to him in a moment, and more often than not Argentina have left two guys wide, hugging the touchline. The extra man and the speed the ball gets across have been causing all sorts of problems for drift defences, especially Ireland’s where the outside-centre, the guy who traditionally shuts off the route to the wide man, finds himself two on one and, instead of slamming the door, has to back-pedal.

If you have a recording of Sunday’s game, you will see what I mean. Usually at least one of the back three is involved, but the outside-centre Matías Moroni, a more than adequate understudy for Marcelo Bosch, or possibly Lobbe, even a prop, were out there when the ball was switched wide.

Argentina still have the big scrum, but they use it more strategically these days, instead playing an all-court game in which the role of Lobbe is increasingly fascinating. He has long been the lion at the heart of Argentina, but at the age of 33, he’s also becoming more and more the brain of the pack, standing off rucks and mauls, instructing rather than getting embroiled.

It is instructive of the clever way this Argentina side go about their rugby. The passion is still there, but there’s the eye for detail as well.