A-Z of betting: O

O is for . . .

Objection: Complaint lodged by a jockey after the end of a race, for one of two reasons - either they were indeed seriously impeded as they went about their normal, lawful business of attempting to win, or they made such an almighty hash of things when the money was down that it is vital to shift the blame. The ratio of the former to the latter is generally reckoned to be about 1:10.

Official: Not a word to treat with the greatest of respect - particularly when it is followed by "going", although given the bizarre system which gives clerks of the course responsibility both for assessing the ground and maximising the gate revenues, they can hardly be blamed for a touch of subjectivity. Sometimes it seems that you can go for months, through winter downpours and summer droughts, when there is not a single going return without the word "good" in it, and this despite the existence of an alternative which seems to work well enough in France. Anyone who travels to Longchamp for the Arc quickly becomes familiar with penetrometer readings, returned as a whole number and a decimal place (1.4, for instance, or 4.7), and appreciate that even a subtle change in the reading can indicate, for example, just how fast the ground is drying. British clerks, however, stick stubbornly to their meagre total of seven basic descriptions - and so would you, if you had been telling outrageous porkies for years and thought you were about to be rumbled.

Overround: The bookmaker's theoretical profit margin on a set of prices, and though it requires the application of a little basic maths, a concept which all punters should understand, since the lower the overround, the better the betting value on offer. Anyone familiar with this process is hereby excused. Everyone else, sit up straight and pay attention. To calculate the percentage chance a price such as 2-1 represents, simply divide the left side by the right, add one, and then divide 100 by the result. Thus, 2-1 is: 2/1 = 2, + 1 = 3. 100/3 = 33.3%, while 15-8 is 34.8%. (Alternatively, consult the very handy list of prices and percentages in any decent racing diary). Do try to keep up, Wakeham minor, and don't do that, Ricketts, you'll spread germs. Now, add together all the percentages for a particular book, and you should get a number greater than 100 (if it is less than 100, the book is "under-round", and there will be some serious value available). That extra percentage on top of 100 is the bookie's margin. Anything up to about 15 per cent offers fair value, and 15 to 25 per cent is an average overround, while anything above 25 per cent is best avoided. With a little practise, this is a vital exercise which becomes second nature.

Owners: All owners - with the exception of those in pounds 400-a-year clubs with 500 members and a couple of horses - fall in to one of two categories: rich, or reckless. The best type of all, from a trainer's point of view at least, is the owner who is both, for as many generations of handlers have discovered, even the sharpest and most ruthless of people tend to lose every critical or suspicious faculty the instant they part with money for a horse. An accountant who predicted profits for their company of 10,000% on turnover, for instance, would be sacked on the spot. If a trainer, on the other hand, vaguely hints that the horse they have just bought for a rock-bottom 10,000 guineas could make up into a Festival contender one day, they will keep sending him fat cheques until, and indeed probably even after, the nag in question has been soundly beaten in a seller at Fakenham.

Orders and off: The magic words which, when spoken over the Tannoy in an apparently empty betting shop, can summon dozens of punters from thin air to create an unseemly ruck at the window. Hanging on to your bet until the last possible moment to try and nick another eighth of a point about the favourite is all very well, but somewhat self-defeating if you need the speed of an athlete and the attitude of a bouncer to take advantage. If betting just isn't the same without the last-second adrenalin rush, you could always move to Ireland, where the attitude to bets in running can be far more understanding, and the racecourse Tote has been known to accept bets on, say, a two-mile handicap hurdle when the leaders are about to leave the back straight for the final time.