CRAIG WATSON did Amir Khan a huge favour by dropping him on to his posterior at the ABA Championships in Preston last month. It was the moment that ended months of unseemly prevarication by convincing the young prodigy and his handlers that it is time to embrace the professional code before his reputation is tarnished any further.

Some will argue that if Khan could resist the big bucks a while longer, he would garner more riches in the long run by virtue of a more rounded amateur education. This is complete nonsense. Amateur and professional boxing have about as much in common with each other as the Sunday Sport and the novels of Dickens. If amateur boxing is supposed to be providing an education, it is teaching the wrong syllabus.

The insidious scoring system, where points are registered when three of the five judges press their buttons within one second of each other, is largely to blame. It is a recipe for superficiality, with boxers encouraged to throw punches that have no impact except in the one-dimensional minds of the ringside officials. As Paul Weir, a two-time world champion from Scotland, put it: “It’s all about obvious, single shots the judges can’t miss and that’s no way to get a grounding for potential pros.”

Combination punching is pointless — literally. By the time the judges have pressed the button to register the first punch, the next four have gone unrewarded. Sugar Ray Leonard, who fought in an era when amateur boxing still meant something, was able to string 10 to 15 punches together in the space of a couple of seconds. Amateur boxing would also have you believe that body punching is of minor import. Well, Rocky Marciano compiled an unbeaten professional record by battering opponents about the midriff and arms until they dropped their gloves. He was one of the best five heavyweights of the 20th century but would hardly have registered a point had he wasted too much time in the amateur ranks.

The computerised scoring system was introduced to prevent corruption in belated response to the light-middleweight final at the Seoul Olympics in 1988, when Roy Jones Jr was denied the gold medal after dominating Park Si-Hun, of South Korea. Which is laughable. As anybody with a Mafia-signed cheque in his top pocket could tell you, substituting a remote control for a pencil is about as effective at combating fraud as a bent copper. If you do not want someone to win, just don’t press his button.

Decisions are as ridiculous now as ever. In Barcelona, the first Olympics after the introduction of the new system, Eric Griffin, an American lightflyweight, was judged both individually and collectively to have landed the greater number of punches, but the computer awarded the fight to his opponent. Another boxer was given a standing count without a hit being registered. In the World Amateur Championships in 1999, the Cuba team walked out after a series of absurd decisions.

Why should Khan, himself the victim of a duff decision in the European Championships last year, forgo a stack of cash in order to endure such nonsense? Do not listen to the drivel put about by the ABA that the lad is too immature to turn professional. Floyd Patterson left the amateur ranks at the age of 17 after winning middleweight gold at the 1952 Olympics and went on to become the first man to regain the world heavyweight title. Muhammad Ali won the light-heavyweight gold in 1960 as Cassius Clay, turned professional that year at 18 (the same age as Khan) and proceeded to become the greatest boxer who lived.

Handled sensibly, Khan will make enough money in the next couple of years to provide financial security while learning the professional ropes from the inside. Apologists for amateur boxing like to describe it as a sprint compared to the marathon of the paid game. Fine, but do not then pretend that Paula Radcliffe would get into shape for the London Marathon by doing a 50-yard dash.

A word of warning, however. When Khan turns professional, sooner or later he will get tagged squarely on the chin. Not just once or twice. But again and again, round after round, as surely as concussion follows collision. And when it happens, he will not have a helmet to protect him. It is only then that his true quality will be revealed.

Take the greatest 50 fighters of all time and you will find a group who span the entire gamut of human possibilities. But they have one thing in common: a granite jaw. The likes of Marciano, Jake La Motta and Marvin Hagler wore their durability like badges of honour. But even those who turned the avoidance of getting hit into an art form had no less a capacity to soak it up when necessary.

Take Ray Robinson or Leonard. Better still, take Ali, the best defensive boxer of all. In 1971 he took a left hook from Joe Frazier that would have floored an elephant and was up at the count of three. Three years later he absorbed the best shots of the mighty George Foreman with a smile.

Khan has a photo of Ali above his bed and dreams of treading the same path towards pugilistic immortality. He has taken the first step with his belated decision to prepare for professionalism. He has the technical gifts, but so did dozens of amateurs who failed in the big bad world of paid boxing. How far he travels ultimately depends upon something that is, at present, unknown. The chin.