This is like old times as I look back through sepia-tinted yet enduring daydreams. So it was a long time ago that the championship decider was fought, as it will be tomorrow, between Wales and France.

Throughout the youthful 1970s, the European challenge rested between these nations. The most recent was in 1978, when the rugby genius that was Phil Bennett scored two tries and, after the second, Gareth Edwards's magnificent kick after the restart sent the ball low from his own 22-metre line, from what was then the Taff end of the Arms Park - the very name rings out the romance of yesteryear - to the equivalent position in the France half at the Westgate Street end, some 60 metres away.

In a single moment of a winning vision, the maestro's morale-destroying kick allowed Wales their uninterrupted surge to the grand-slam podium. I watched with longing from a distance: a harmful hamstring had played up.

We all went to Downing Street after that, by kind invitation of the late James Callaghan, MP for Cardiff South and the Prime Minister at the time. We were the bee's knees. None of us believed that more than a quarter of a century would pass before the deed would be accomplished again by Wales. Such are the vagaries of sport.

It was a privileged time, since when a river of tears has been spilt after the many melancholy failures. A sporadic outburst here and there gave hint that the rugby pulse did still beat in Wales. It was not until 2005 that this was confirmed when the grand slam was achieved again. Failure immediately followed.

Time moved so dramatically that those then yet unborn and of greener memories can remember nothing but the overwhelming dominance of England and the continuing presence of France. Each day's favourite may have been tripped up and failed to catch the elusive grand slam, as could again be the case tomorrow, such is the spell that the championship weaves.

But there was no escaping their influence. England and France have been in charge. So much so that television moguls suggested that the final match of the RBS Six Nations Championship should be so arranged that the climax be either in Paris or London. It was given short shrift, so, thankfully, tomorrow has the potential for a rich display.

For sure, this Wales team have been a revelation and, indeed, are the team who have set the championship alight, despite the many reservations others would appear to have of them. There are those who remain suspicious of a team who choose a lightness of touch and do not rely solely on embarking on a bone-crunching trial of strength.

Eddie O'Sullivan, the Ireland coach, paid Wales a compliment last weekend when he said, in choosing to play a forward-orientated game to begin with, that he did not want to create a landscape Wales would have wanted. In other words, Wales want to release the ball into fluid spaces, play a game of wide and unexpected movement. Ireland tried to stop it.

The greater revelation is that, even here, amid the thick and hard-boiled forwards, Wales have been all but immovable. Their defence is tightly knit. Each team have tried to gain the hard yards, as Ireland did on Saturday, but to no avail; even the inches were hard to come by.

In 2006, Wales scored seven tries and conceded 13. In 2007, they scored seven but conceded nine. This season they have accumulated 11 and given away two. Theirs is not a one-dimensional strategy. They are not held to a single “game plan”, a phrase redolent of a strategy but possibly blind to the on-the-field tactics and the changing requirements of the critical 80 minutes of play.

Regardless of what may happen between Wales and France in Cardiff tomorrow, this season can be defined as a successful one for Wales. Against all predictions they have reached their final fixture with - and I am keeping in the forefront the clear-headed judgment of Shaun Edwards, the defence coach - the championship as the beckoning prize. The grand slam, extraordinary as this is, is for later consumption of all teams who reach this stage and a secondary, if precious, indulgence. It is who heads the table that, principally, matters.

If the Wales team's performance is concluded to be a success - and statistically it already is - they must enter unfamiliar territory. They need to manage success. Success needs to be carefully nurtured. Success and failure, winning and losing, hang on a thread. Those on the field tomorrow will need to take heed of this and after tomorrow those off the field will need to tend to the delicate nature of what so suddenly has come Wales's way.