My method for spotting winners at the National

'I did quite well out of bookmaking myself. In my first year at grammar school I cooked up a marvellous scam'

We are approaching arguably the most exciting weekend of the sporting calendar. The Grand National, the US Masters, an FA Cup semi-final, a grand prix, even the start of the first-class cricket season. Something for everyone. Thanks to the Grand National, it is also the biggest betting weekend of the year, and so I will spare my late father an affectionate thought. For he was, at one stage of an impressively varied yet resolutely unsuccessful business career, a bookmaker. In the late 1960s, on the basis that if you can't beat 'em, join 'em, he established a betting shop on Duke Street, Liverpool, only to find to his dismay that, having joined 'em, he kept getting beaten. Which is why I force a wry smile whenever someone trots out the old cliché about never seeing a poor bookie.

That said, I did quite well out of bookmaking myself. In my first year at grammar school I cooked up a marvellous scam whereby I would invent a dozen or so horses, fix their odds, and then stand on a desk performing an excitable commentary in the style of Peter O'Sullevan, or as close to it as my unbroken voice and northern vowels would allow. My runner had, in the meantime, collected bets which, for obvious reasons, I was not permitted to see in advance of the race.

Various currencies were accepted, from hard cash to Bazooka Joe bubble gum to copies of Penthouse. If there was a dog-eared Penthouse placed on a 3-1 shot, which then romped home (as the horses with short odds invariably did), I somehow had to get hold of two more. My runner and I were not above a spot of casual shoplifting to meet the more substantial pay-outs. However, the deputy headmaster - the terrifying Mr Wakefield, universally known as Pegleg - got wind of our racket and brought it to a decisive and indeed rather painful close. I can't remember whether my parents were informed. If they were, I like to think that my dad might have been secretly proud of my enterprise.

His devotion to horse-racing knew no bounds. As a child, I was more familiar with the racecourses of Haydock, Chester, Cartmel and York than with any adventure playground. And yet, curiously, he never took me to Aintree, the nearest to home. To this day I've never been to the Grand National, but for more than 30 years have been glued to it on television. I first watched the race in 1967. I was five, desperate to spot my dad's distinctive brown trilby bobbing among the tens of thousands of other distinctive brown trilbys, no mean challenge on a small black-and-white telly.

That, of course, was the year the National was famously won by the 100-1 shot Foinavon - whose jockey John Buckingham, became a valet and, seven years ago today, consoled a distraught Jenny Pitman after her Esha Ness won the National that never was. That's the thing about the National. It never fails to produce a story, often dramatic, often poignant, often romantic, sometimes all of the above. Indeed, in my experience, that certainty can help to steer you towards the winner. Stuff the formbook, you can bet your bottom dollar that the race will produce a great story so, before investing your bottom dollar, consider the potential stories.

Last year, for example, many punters were seduced by the idea of Nahthen Lad winning it for Jenny Pitman in her valedictory National. But some of us spotted similar romantic-story potential in Paul Carberry's attempt to ride the first Irish winner since his dad, Tommy, guided L'Escargot to victory in 1975. Which he duly did. And I'm delighted to say that I had a tenner each-way on Carberry and Bobbyjo at 16-1.

If you want to make doubly sure of backing the winner of the Grand National, apply the equally unscientific O'Sullevan test. In the voice of Peter O'Sullevan (my own impersonation has improved considerably with age, by the way), you say, excitedly, "and X wins the National," inserting the name of a particular horse.

If it sounds right, back it. If it doesn't, don't. For instance, Call It A Day, the mount of Richard Dunwoody, might have been one of last year's favourites, but the name wasn't right. For the same reason, I never fancied Lastofthebrownies, fourth in 1989 behind the perfectly named Little Polveir.

Other recent winners, such as Earth Summit, Royal Athlete, Rough Quest and Mr Frisk, all passed the O'Sullevan test. As, of course, did Red Rum, the ultimate Aintree winner, who lived round our way. In fact, every time he ran in the Grand National, the whole town loyally backed him and duly raked in the winnings. All except my dad, the man who knew too much form.