AS Ben Hogan and Bobby Jones both said, champions can do no more than beat those who are around in their given time.

Yesterday, on BBC Radio's 5 Live, Denis Law was a guest, and what came across was not just the lasting admiration for a wonderful player but the genuine affection of those for whom he provided so many colourful memories.

Sir Henry Cotton used to maintain that the great champions are always true originals with a style, and frequently a presence, all their own. That the carbon copies maybe very good but they never quite match the real thing.

Gardner Dickinson, he would say, aped Hogan right down to the white cap but fine player though he became, he never got within a cooee of being the golfer Hogan was.

Law was very much a one-off, a distinctive footballer whom to this day few have the slightest trouble in seeing again in the mind's eye.

In Campbell's programme, Law was not to be drawn on which of the two Manchester United sides which won the European Cup could be deemed the greater, merely echoing George Best's use of an old joke when Peter Schmeichel opined that the class of '99 would put 10 goals past the class of '68. To wit, ''Very probably but don't forget that the team of '68 are all over 50 now ''

It is probably correct to assume that the games-players born to true greatness would find their way in any era and if not in one realm of sport then in another. Otherwise, comparisons between players of different periods are apt to be compromised by the changes which have taken place over the years.

Not so long ago, at a Hall of Fame dinner in London, two of the inductees were those legendary locks, the Springboks' Frik du Preez and the All Blacks' Colin Meads. Yet du Preez was just 6ft 2in tall, while even ''Pinetree'' stood no more than 6ft 4in. They would be dwarfed by most of today's international second row forwards.

However, you still have to be careful. Had Kevin McKenzie played for Scotland 25 years ago, many would be saying that he was very good but, of course, at his size, he would never have been capped in the modern game.

The decline in the amount of grass court tennis played has, among other things, inevitably led to markedly fewer players favouring the so-called Continental grip. In addition, the advent of the more powerful, larger-headed, graphite-framed rackets has had an effect, not least on the women's game.

Yet I have heard Ivan Lendl insist that the biggest single difference over his career has lain in the development of the latter-day, pressured tennis ball.

Not dissimilarly, Jack Nicklaus is but one of the leading names of the day who avers vehemently that it is less the big-headed metal woods which threaten the continuing validity of some of the most revered golf courses of yesteryear than the distance the ball now travels.

At Raeburn Place on Monday there was much debate as to whether the Scotland players, the excellent Gavin Hamilton apart, were really as good as the Jim Aitchisons and Willie Nichols and various others in between.

But, perhaps predictably, about all that was agreed was, firstly, that the three-day friendlies against English Counties and overseas touring teams were far removed from the very-much-for-real World Cup encounters of today. And, secondly, that the heavily lacquered white ball is another thing again, posing some unfamiliar problems of swing and seam.

In football, too, the ball has changed and can be bent hither and thither in a way which was just not possible with the heavy leather versions of bygone days which, when sodden, could feel as weighty as the proverbial cannonball. Especially against a flattened forehead . . .

Tactics are also greatly altered. When, in my own modest football career, I was snatching odd games for Edinburgh University and the Spartans in the East of Scotland League, it was still the vogue to play with five forwards. Yet, by the time I stopped, that also had been revolutionised.

Indeed, I have told before of how, the day before I played my very last game, I was under the blades of a hairdresser who, as always, talked football throughout the short back and sides.

When he finally desisted, he surveyed the remaining strands of my thinning thatch and inquired, cheerfully: ''Well, how do you want them - 4-2-4 or 4-3-3?''