Welcome to the last chance saloon. For the protagonists, every interprovincial is a big game but whereas before there was at least another game or two, now they find the safety net has been removed. As Leinster captain Kurt McQuilkin cryptically puts it, "it's now or never".

Sponsor's brew all round then come 4.00 p.m. or thereabouts, with three provinces having cause for celebration amid drowning of sorrows for the loser. Traditionalists might disagree, but there is arguably a bigger, more important, and certainly more intriguing issue than simply the question of who wins the 1997 Guinness Interprovincial title this afternoon. That is, which three (and there definitely will be three again) qualifies for next season's European Cup?

Munster, the defending champions and champions again in waiting, are the only province who can breath relatively easy come 2.30 this afternoon. For their hosts Ulster, and the Donnybrook combatants of Leinster and Connacht, there is a three cornered fight for the two remaining European Cup spots. With the wooden spoon, comes consignment to 1997/98 European Conference.

Munster could also consign calculators to the dustbin were they to beat Ulster, thereby securing their 12th interpro championship and third grand slam in four years (and eighth overall). In that scenario, Leinster and Connacht would be assured of their place in next season's European Cup, with their Donnybrook encounter merely deciding who finishes second and third. But they won't know that until it's over and so come kick-off it might as well be win or bust.

Because, were Ulster to beat Munster then, barring a draw in Donnybrook, both the title and the third European Cup place will be decided on points' difference. Going into the final round of games, a mere nine-point swing covers the aggregates of Leinster, Connacht and Ulster. In the unlikely event of two teams finishing with the same points and points difference, then their final standing will be decided by their respective number of tries. As things stand, all four provinces have scored three tries.

There appears to have been a levelling out of standards, as evidenced by two of the games (the ones involving Leinster) being decided in injury time. The scoring patterns between the four provinces have also been strikingly similar, with each province averaging between 18 and 22 points per game.

To recap then, all bar Ulster are in with a chance of the title, while all except Munster have still to secure their European Cup qualification hopes. Each of the provinces has their own respective targets going into today's games.

Munster - A draw would secure the championship. To be denied the title, they would have to lose to Ulster, with Leinster or Connacht winning and the combined margins adding up to 27 or 34 points.

Leinster - To win the title, they would need to beat Connacht, and Munster lose to Ulster, by a cumulative total of 27 points or more. A draw would ensure their qualification for next season's European Cup. Were Leinster to lose, they could be squeezed out of the 1998/99 European Cup if Ulster beat Munster, with combined victory margins of nine points or more.

Connacht - To win the title they must beat Leinster, and Munster lose to Ulster, by a cumulative total of 34 points or more. A draw, meanwhile, is their minimum requirement to earn qualification for next season's European Cup with favours from elsewhere. Defeat, coupled with an Ulster win over Munster, would see Connacht miss out on the 98/99 European Cup on points difference again regardless of the final margins.

Ulster - They must win to have any hope of climbing off the bottom of the table and thereby qualifying for next season's European Cup. In that scenario, a Connacht defeat at Donnybrook, or a Leinster defeat (with the combined margins totalling nine points or more) would suffice. Thus a nine-point win over Munster, provided the Donnybrook tie yields a winner, would pull them into the top three.

As can be gauged from all of this, both Leinster and Connacht approach their clash nervily, in the knowledge that either could conceivably finish anywhere from first to last. Neither can afford to rely on Munster beating Ulster.

"You couldn't be relying on that," admits Leinster manager Jim Glennon. "It's within our own power. We haven't even looked at the mathematics of it."

Wayne Gatland, Connacht's coach said: "We've nothing to lose and everything to gain. All the other provinces, they're the ones under pressure." Qualification for the European Cup would be a boon for the game in the west. "It would be huge," he says simply.

The damage on missing out for Ulster, if only for a year, would be immense. As coach Davey Hazlett points out: "In rugby terms it would be a disaster in terms of exposure to the top teams for the players and finance, either for being in the Cup or crowd appeal. The sheer promotion and projection of the Cup would be greatly missed. So it's a huge game."

Almost carefree in comparison to all their counterparts, Munster head north with a clear objective in mind; "to win the interpros" says manager Jerry Holland.