It is a measure of McGeechan's achievement as coach that Scotland, despite a rugby-playing population of only 25,000 (barely half Wales's and a paltry fifteenth of England's) have become almost impregnable at home. Australia and England have been the only winning visitors here since 1988 and Wales have not done it since Terry Holmes was captain in 1985.
To have inspired this, with a precious Grand Slam thrown in in 1990, has elevated McGeechan's status to an unprecedented level - so that his farewell to coaching once Scotland have played England next month will be to take the Lions to New Zealand. He was the winning coach in Australia in 1989, and no Lions coach has ever been asked to undertake a second tour.
Moreover, he is adding to his credentials all the way until his time is up. So Wales, having to the vociferous delight of all Scots disposed of the English, may fancy themselves for at least a Triple Crown. But Scotland, too, are one step along that road and, after heeding England's vulnerability in Cardiff, believe themselves capable not only of beating Wales but of winning at Twickenham (an even less pregnable fortress than Murrayfield) for the first time in 10 years.
What makes it still more impressive is that a couple of months ago Scotland appeared in some distress, their Five Nations preparations disrupted by the reconstruction of Murrayfield and the failure to stage an autumn international. McGeechan was not best pleased.
Sole, White, Lineen and Tukalo had added their retirements to those of Jeffrey and Calder. The spread of talent seemed desperately thin. Enter McGeechan for another piece of rebuilding. The coach has triumphantly blended a team from disparate sources which easily beat Ireland and two weeks ago should have won in France for the first time in 24 years rather than losing 11-3. 'I'm pleased with the way it has fallen into shape,' McGeechan said, in that undemonstrative way of his. 'It's just another challenge and it's up to me to get the priorities right for a different group of players with different strengths and weaknesses.'
To take a specific example, Andy Reed, the 6ft 7in lock whom Cornishmen thought was one of their own until he was caught wearing a Hearts scarf, had scarcely made the Bath first team when Scotland picked him, yet he has been a remarkable success in line-out and beyond. As ever, much of the credit has gone to McGeechan - though Jack Rowell, the Bath and England A coach, might beg to differ.
It was Ieuan Evans who said that McGeechan 'was the best coach I've ever been under' after the '89 Lions tour. As Evans now captains Wales, he may consider Alan Davies to have assumed that mantle, but even so there is little doubt that McGeechan opened Evans's eyes to the fact that there was a world game out there from which the Welsh had consciously excluded themselves for too many years.
The change in attitude, in fundamental philosophy in fact, goes a long way to explain why Wales appointed Davies in the first place, why they beat England and why they have a chance of beating Scotland today where two years ago on their last visit they had next to none. It has been a painful but somehow purifying process.
'Scotland will have the added impetus of it being Ian McGeechan's last home game as coach, so there will be a tide of emotion which will make it difficult for us,' Evans said. 'I'm hopeful we can cope with that better than England did but it's always very difficult to win at Murrayfield.'
All perfectly true. The problem is that to win Wales, even with their favourite referee, Joel Dume, again at the whistle, will have to adopt a radically different mental approach from the English match. This time they know that gung-ho tackling and sticking the ball relentlessly in the air will not suffice because, as Evans says, the emotional tide on which success then depended will now be running for Scotland.
There are thousands of Welshmen in Edinburgh this weekend, reminiscent of the early Seventies when entrance to the terraces was by paying at the turnstile. But because those days are gone, most of the red-decked horde will remain ticketless, and the imbalance of support inside the new-look, soaring stadium means it is not hot blood but cool heads and lucid tactical appreciation that will be required. And those are qualities which Wales, even the new Wales of Alan Davies and Ieuan Evans, have still to show they possess.
----------------------------------------------------------------- SCOTLAND V WALES - (at Murrayfield) G Hastings Watsonians, capt 15 M Rayer Cardiff A Stanger Hawick 14 I Evans Llanelli, capt S Hastings Watsonians 13 M Hall Cardiff G Shiel Melrose 12 S Gibbs Swansea D Stark Boroughmuir 11 W Proctor Llanelli C Chalmers Melrose 10 N Jenkins Pontypridd G Armstrong Jed-Forest 9 R Jones Swansea P Wright Boroughmuir 1 R Evans Llanelli K Milne Heriot's FP 2 N Meek Pontypool P Burnell London Scottish 3 H Williams-Jones South Wales Police A Reed Bath 4 G O Llewellyn Neath D Cronin London Scottish 5 A Copsey Llanelli D Turnbull Hawick 6 E Lewis Llanelli G Weir Melrose 8 S Davies Swansea I Morrison London Scottish 7 R Webster Swansea Replacements: 16 K Logan (Stirling County), 17 G Townsend (Gala), 18 A Nicol (Dundee HSFP), 19 C Hogg (Melrose), 20 G Isaac (Gala), 21 I Corcoran (Gala). Replacements: 16 R Moon (Llanelli), 17 A Clement (Swansea), 18 A Lamerton (Llanelli), 19 J Davies (Neath), 20 A Reynolds (Swansea), 21 P Kawulok (Cardiff). Referee: J Dume (France). Kick-off: 2.30.Reuse content