RUGBY/ Scotland v Ireland: If Ireland could buy two matches this season, this would probably be one of them. The other, admittedly scarcely in telescopic range, is the collision with Argentina in the final pool game in Australia next October. Win these two pivotal games and Ireland are well set for at least reasonably successful campaigns in both the Six Nations and the World Cup. Lose them, and well . . .

It's also no co-incidence that Ireland's two best championships in the last 13 years have been the only two campaigns in that time where they have won their opening games. Optimism, however guarded, surrounds this Irish team and emanates from within, and with good reason. But anything less than victory against the dastardly Scots in Murrayfield tomorrow and already it will have been misplaced.

There are, admittedly, nine good reasons why it mightn't happen, and Ireland's only notable away win in the last three years was against a desultory Wales. Irish teams have also travelled over to Murrayfield with even greater confidence, however misplaced, since the last win in Edinburgh fully 18 years ago. This particular Scottish outfit mightn't be a team of all the talents, but they've enough in their armoury to discommode Ireland again, and once more will be marshalled from the hilltops by Messrs McGeechan and Telfer.

While Ireland's setpieces improved immeasurably in the autumn, as even Malcolm O'Kelly was at pains to point out at the time, the Australian and Argentinian lineouts weren't on a par with Northern Hemisphere sides, and Scotland's - with his old foe Scott Murray peerless - is as good as any around.

Such is the near telepathic timing between Gordon Bulloch and Murray that it's an almost guaranteed source of primary ball every time. Being equally secure off their own ball and trading at parity here would probably be a result for Ireland, and it's worth recalling that in Murrayfield two seasons ago, and even in much of last season's championship, a malfunctioning lineout did more than anything to unhinge Ireland's gameplan.

Asked how he rated the Scottish lineout, Eddie O'Sullivan commented: "Not just the lineout, but at the moment the Scottish scrum is probably one of the best scrums in the Six Nations. It did a real job on South Africa, which doesn't happen very often, and despite the legend of their rucking game, they've developed one of the better mauling games around as well."

With the streetwise Bryan Redpath calling the shots and in a rich vein of form, and Gordon Ross' stratgegic kicking preferred to Brendan Laney's or Gregor Townsend's more expansive game at outhalf, Scotland's gameplan is likely to be less ambitious, but therefore also easier to put into action. In short, the Scots are again well-equipped to starve Ireland of ball for stretches.

In previous visits here this has compelled Irish playmakers to try too hard to make something happen, thereby coughing up ball again and leading to further bouts of frustrated defence. Before they knew it, the game was gone.

Chatting to some of them yesterday along a humming Princes Street under clear blue skies, with the flags from the established hostelries already giving Edinburgh a real Six Nations ambience, it's clear that the Irish players know what to expect.

The temperature was close to zero even during the day yesterday, and Ireland eventually trained for two hours on Belergo High School's all-weather pitch after intended run-outs at Heriot's and Currie were abandoned because of frozen pitches. Tomorrow could be even colder, but Murrayfield has undersoil heating - so Scotland's training was unaffected.

In any event, nine times warned is nine-armed and O'Sullivan has underlined the lessons of recent history this past couple of weeks.

"I think we'll go out there with a less cocky approach," admitted Brian O'Driscoll earlier in the week. Nor will they be taken aback by the furious physicality and intensity Scotland will bring to the party from the kick-off.

This is Six Nations' rugby, not autumn Tests, and the exchanges are liable to be altogether more feisty. Unlike two years ago, Ireland have to keep their shape in withstanding the storms which the Scots will inevitably whip up, throw in a few big hits and disrupt them at the breakdown (cue Keith Gleeson). If they then keep their heads with the ball, there's no doubt they have the more potent game out wide.

The smoke signals from Edinburgh are that the pacey Andy Mower has been picked in part to play in David Humprheys' face all afternoon. With O'Driscoll also a marked man, and bearing in mind how McGeechan's sides flirt with the offside line, the less leeway Andrew Cole gives here the better.

It's a massive game for Humphreys, and the little Ulster maestro's performance will surely be a pretty good barometer of Ireland's. Ulster's somewhat conservative and forward-orientated game hasn't brought the best out of him this season. But if Victor Costello, Kevin Maggs and Co make the hard yards close in, something which didn't happen two years ago for Ronan O'Gara, then Humprheys will have Peter Stringer's service and the space to play a flat game and bring Ireland's superior match winners into play.

More than the Scots, they also have the strike power to score unstructured tries off turnover ball or counter-attacks. Ultimately this is a collection of Irish players pretty much in their prime. Only Humphreys, Reggie Corrigan and Victor Costello have experienced more defeats than wins.

Whether winning ugly, or winning pretty, Ireland have it in them to do either.