Perfection in sport occurs rarely and in boxing almost never. Yet after Joe Calzaghe's imperious victory over Roy Jones Jr (see page 72), the Welshman retains a perfect record. He has fought 46 professional bouts and won them all.

Only Rocky Marciano, the American heavyweight who dominated the early Fifties, has gone any better: he accumulated 49 consecutive wins and it is his unblemished record for which he is remembered today. Calzaghe now has the opportunity to call time on his fighting career and establish a legacy of the quality of Marciano's.

He has now, arguably, become the greatest British boxer of the postwar generation. He is, possibly, the greatest fighter of all time in the super-middleweight division. While undefeated, he remains an undisputed giant of the sport.

However, before him now stands the temptation that has snared so many great boxers before him. He could carry on fighting and carry on collecting seven-figure paydays. The obvious risk is that he loses and that his 100 per cent record goes down with him.

His age, 36, is one where boxers are in decline. There is no sign yet that Calzaghe's talents are declining and this is another factor that may persuade him to fight on. In boxing, however, one big punch can age a man for good.

Calzaghe has suggested strongly that he will retire but after Saturday's fight he said he was not so sure. Yet at this stage of his career, there are no worthy challengers left for him to fight, he has nothing left to prove. He has fought throughout his career with impressive class; the last classy move left for him is to retire from the sport and remain forever an unbeaten champion.