Sarah Sands: Skip the hanky-panky and you just might score

George Best used to tell the story of the night porter who brought a bottle of champagne to his hotel room shortly after he had walked out on Manchester United. The football star lay sprawled on a bed with casino winnings and a Miss World. "Would you mind if I asked you a question, George? Where did it all go wrong?"

Fabio Capello would not see the joke. He understands that the perks of football destroy the players. Last week he was being talked of as if he'd converted the England football team to Opus Dei after he said to leave their wives and girlfriends at home. Some commentators have been puzzled that someone from Milan should behave like a German, overlooking the contempt that the industrious north of Italy has for the lazy south.

In fact, Capello has solved a simple equation. In order to succeed, you need to focus. It's the quality to which the investor Warren Buffett, a man who makes even more money than Premier League footballers, attributes his entire fortune.

I've been reading Buffett's best-selling biography, The Snowball. He is not a man who could be accused of living life to the full. In his early professional years he sat up in his pyjamas, reading financial reports and drinking Coke. At the height of his powers and fortune, he would eat a hamburger, call out for a Coke and look at more financial screens. He was hurt and puzzled when his wife finally moved out. After she died, he declared that the purpose of life was to be loved, but the accumulation of money appears to have remained his driving passion.

His championing of thrift was partly thinking that spending money was a distraction from making it. If you see a businessman behaving lavishly, the chances are that something is amiss. Bernard Madoff knew that the way to convince clients of his wealth-making abilities was to live quietly.

If stock investors, whose sole purpose is making money, can't be bothered to spend it, there is less excuse for footballers to do so. We look back on the arrival of the wives and girlfriends in Baden Baden in 2006 as the last days of Rome. Shops shipped in £200,000 worth of luxury goods and could barely wrap it fast enough. The women were dressed to undress. What were poor befuddled footballers supposed to do on the pitch, after being licked to the bone by WAGs still wearing the price tags on luxury lingerie?

Recently, the England captain John Terry took issue with the papers for inaccurately reporting a six-figure team bar bill at a fancy Chelsea club. The sum had not seemed large by footballer standards, but Terry saw the way the wind had blown. High-spending entertaining was not merely vulgar: it was also unserious.

For some time, football has been out of line with the ferocious discipline of other sports. Look at the joylessness of tennis, where we have long since ceased to expect charm from Andy Murray. How charming would you feel after undergoing the kind of psychological training that even Dick Cheney would find too dark?

It may not be true that behind every fortune lies a crime, but it is has to be right that extraordinary success is not founded on a rounded approach to life. Greatness is the fruit of obsession. Footballers have wanted the rewards of success, but the reward is success. It is beyond Darwin, who called only for the survival of the fittest. This is the fittest of the survivors. What Capello was trying to say, when he told his players to take the iPods out of their ears, was heed the wisdom of Buffett: "Intensity is the price of excellence."