Jim Telfer has seen it all before, but for Graham Henry it is a leap into the dark. When Scotland's head coach made his debut as a player in the Five Nations 35 years ago, Henry, his opposite number, was at college in New Zealand, his experience of the tournament limited to a flickering television screen and Bill McLaren's burr.
Telfer has tasted the highs and lows in the championship as a player and as a coach, giving him an insight Henry lacks. "Wales will come to Murrayfield expecting to win," said Telfer. "Now that they are not losing players to rugby league, they are again looking a good side; but it has gone wrong for them here often enough in the past."
Henry knows only to expect the unexpected. He took over as the Wales coach last August and it was said at the time that he could not have had a tougher baptism: the World Cup holders South Africa, at Wembley. Five months previously, Wales had leaked 96 points to the Springboks: Henry may have been portrayed by his employers in a poster campaign as the Great Redeemer, but no one was claiming he could turn water into wine. As it turned out, three things stood between Wales and their first victory over South Africa - a disputed penalty try, the intervention of a streaker late in the game when the Springboks were trailing, and the brilliance of Joost van der Westhuizen. A defeat it may have been, but the wine flowed. A nation started to believe in itself again.
It was only when Henry walked down Edinburgh's Princes Street in Thursday's fading light that he started to appreciate what Telfer had long known. As hordes of unknown figures clad in red and white greeted him rapturously, Henry understood that the championship was about more than rugby. In what other tournament would a wooden spoon decider be a guaranteed sell-out?
Scotland are adding to Henry's concerns by happily portraying themselves as underdogs ("cobblers", said the New Zealander) even though they have lost at home to Wales only once in 14 years. Scottish rugby may be in turmoil, but the Welsh game is hardly in fine fettle following the collapse of the putative British League and the continued rebellion of Cardiff and Swansea. Wales needs a healer as much as a redeemer.
Scotland, like Wales, have a core of experienced players and they should have the edge in the front five, particularly if the referee Ed Morrison frowns on Henry's tactic of having his forwards arrive late for a line out.
Wales suffered a blow yesterday when the experienced prop David Young withdrew from the side because of a calf strain. He will be replaced by Swansea's Chris Anthony. The Scots, with Tom Smith back to full fitness, look stronger up front.
But it is behind where Wales are strong. The half-backs Robert Howley and Neil Jenkins are both Lions, as are the reunited midfield duo Scott Gibbs and Allan Bateman. "This is the year when we have to do something," said Gibbs. "Defeating the other Celtic nations will not be enough. We have to do something against England and France."
"We are good enough to win the championship and even the Grand Slam," said Bateman. "It is all about pulling together as a team. Graham Henry has introduced a more relaxed regime - training is shorter but more intense. He laughs a lot and the players, unlike last year, are not feeling any pressure."
It should be fast and loose today. Home advantage for Scotland will be slightly offset after Welsh supporters snapped up 10,000 tickets the host union was unable to sell, but that sums up Henry's problem: Wales expects, Scotland does not.
Telfer, in his last championship campaign, is cannily exploiting that. A Scottish win would add to his renown, and with four of Wales' front five making their championship debuts, and with the fifth, the hooker Jonathan Humphreys, having played only once in the last five weeks because of a back injury, Henry is facing the biggest test of his coaching career.
Out of the light and into the dark. Telfer, since resuming the responsibility of heading the coaching of the national team this time last year, has presided over just a solitary victory, over Ireland in Dublin, in eight full Tests.
While that record has led many critics to brand Scotland likely wooden spoon candidates, the coach is quietly optimistic about their prospects.
"I don't think there is that much difference between the teams. We played reasonably well at the back end of last year and we have taken something from that."
