One of the reasons the Olympic movement has rejected rugby union since 1924 is a feeling that it is too predictable. Well, if any of the movers and shakers would care to join us in Rosario today and give any sort of steer on what will happen between Argentina and Scotland, they would save an awful lot of frayed nerves. This is one game where nobody has a clue about how it is going to pan out.

These are two substantially reshaped teams, meeting in a place that Scotland have not visited for 14 years. Now, to cap it all, the International Rugby Board issues a new set of instructions to referees that will make the breakdown even more of a lottery than normal and could mean the result depends on a shootout between two of the deadliest penalty gunslingers in world rugby, Chris Paterson for Scotland and Frederico Todeschini for the Pumas.

Frank Hadden, the Scotland coach, is not particularly happy about it. “The rulings have the capacity to make a massive impact. It will be interesting to see how they are interpreted and we will be having to go in warily,” he said. “It is like the directive before the World Cup, it will give more leeway for defenders and mean more penalties against attacking sides.”

Recent experience in big games suggests that anything that helps defences is not going to help the game as a spectacle - cynics even suggest it is a move to discredit the existing laws before the experimental ones are introduced - and the fear in the Scotland camp is that they will help Argentina with their controlled, forward-led pattern.

Santiago Phelan, the new Argentina coach, has made it clear this week that even though he has had to rebuild the side, he has not had time to make many changes in style. So, it is a case of new faces, but still the same massive pack creating holes for the pacy backs to run into. The only question is whether a side that is half home-based - and therefore amateur - can deliver that style as well as the World Cup squad.

But as Hadden pointed out, if any country in the world can do that, it will be Argentina. Even though there are not many players in common, there are parallels with the side the Pumas assembled to face the Lions three years ago - a match where the British Isles were lucky to escape with a draw.

The other great unknown is how Scotland will perform. They may have lost only four players to the French boycott of international tours this summer, but they have also lost half-a-dozen England-based players to injury and, like Argentina have been forced into a rebuilding exercise.

But don't thank Hadden, thank Andy Robinson and Sean Lineen. It was these two coaches who put together the Scotland A team on which the new look is substantially based. They brought Graeme Morrison and Ben Cairns together in the centre, devised a game plan that gave Thom Evans the space to show what he can do on a fast pitch and gave Alasdair Strokosch and Johnnie Beattie the chance to earn their senior recalls.

As always, however, the key is likely to be the Scotland half-back pairing. If Mike Blair, the captain, and Dan Parks can fire, they are in with an excellent chance. If they flop, as Parks did against Italy in his last outing in the RBS Six Nations Championship, the result is close to a foregone conclusion.

Blair, for one, expects the former, not just because he has faith in his team-mate to bounce back, but because he believes that the whole game is set up for Parks to deliver. “The pitch we are playing on is quite small, just like the one Dan [Parks]

is used to playing on at Firhill in Glasgow and where he has had an excellent season, especially with his kicking game,” Blair said. “He can boss the game because he will be able to play the dimensions of the pitch so well.”