IN MUHAMMAD ALI’S win/loss record, he gets the same credit for the Thrilla in Manila against Joe Frazier, for the Rumble in the Jungle against George Foreman and for beating Richard Dunn in the Mauling in Munich (I made up that label).

According to folklore, as Ali went back to his corner at the end of one of the rounds in the Dunn fight, he turned to a ringside television producer and said: “Get those commercials in quick. I can’t hold this sucker up any longer.” This autumn the All Blacks have been holding up the suckers of British and Irish rugby, they have been that superior.

When putting this Grand Slam into perspective, it is as well to recall that it is the second of the year. Wales achieved their own in the Six Nations, and that included an away win over a France team that had found itself after suffering early season horrors. But right now only England and South Africa live on the same sporting planet as New Zealand, and even they aren’t their next-door neighbours.

Grand Slams don’t always tell us everything. It is an irony that the 1978 All Blacks, the only New Zealand team to achieve the feat in these islands before Tana Umaga’s marauders, were far from the best New Zealand team I have seen here. In fact they were almost the worst — the sides of 1963, 1967, 1972 and several since were better. So were Tana’s troops.

How good are this latest lot and how good can they become? Very good indeed; possibly brilliant. They are outstanding at the basics of handling, lineout, tackling and, the most basic of basics, passing. And if that sounds like damnation with faint praise, it is not. They were confident during this tour, kicked goals and a few of their reserves were interchangeable — although only a few. The suggestion by Frank Hadden, the coach of Scotland, that New Zealand could find four teams that would have won the Grand Slam is garbage.

And they mask weaknesses, a tribute to Graham Henry and his coaching. True greatness can be conferred only by winning the World Cup, as Henry well knows, but it is harsh to suggest that New Zealand are not potentially a great side just because they have not yet won it. They were also ambitious and good to watch.

In another sense, greatness comes down to the quality of the opposition. That is partly why the 1978 All Blacks were so fortunate. They fought Richard Dunn. Four times. And with reference to the 2005 bunch, the equivalent of Ali holding up Dunn was for New Zealand to take pity on the opposition by fielding second teams against Ireland and Scotland, just to make it a contest.

You sense that the Irish and Scottish rugby authorities were bursting to complain about this insult — except that the only way they could have done so was by winning. That shadow team would also have been good enough on the day to beat Wales, who ended the autumn series with 12 players absent through injury.

It jarred every time you heard New Zealand insist that they were not here for the Grand Slam, that this was some kind of development exercise. Drivel. They were desperate for the Grand Slam, desperate not to lose any game, as they always are; and they selected teams with a view to winning every one.

However, there is occasionally an in-built weakness in the idea that a team cannot be lauded if the opposition is dire. Sometimes the opposition is only allowed to be dire.

To beat Dunn did not add to Ali’s status, but it didn’t mean he was not a wonderful fighter, either. These Kiwis have not met their Frazier and Foreman yet, but that is not to say that when they do, their opponents will not end up horizontal.

Two years out from the World Cup, another significance of the past month is not what we learnt about the All Blacks, but what we learnt about the home unions. Suddenly those two years are compressing madly. A lack of quality and depth has been ruthlessly exposed, even in an England team that tested New Zealand to the limit but left the impression that the players may already be reaching their maximum.

But it is not in terms of basic talent that the home teams have most to learn. What is so striking about New Zealand in any era is the way they maximise themselves. They may have a weak team, they may have a promising team, they may have a great team, but they come to play, they come to win, and they come at a peak. The old coaches’ claptrap that “we are improving and could be better next time out” has no currency with them. They came for the Grand Slam and they left with it. They leave happy.

It has been a faintly bizarre autumn series because so many of the teams have been labouring without top players. Australia and Wales were especially savaged by injury — at the last count, they had 21 absentees between them. Ireland and France were sorely afflicted. To a lesser extent, so were England and Scotland. It seems to have become part of rugby’s uncomplaining code that nobody must make suicidal noises as the next raft of players disappear to x-ray.

And yet here again is a song of praise for the dominant team of this autumn. The All Blacks, too, fielded teams denuded of their finest players. In their case it was by choice. That is, at the very least, a portent of greatness to come.