Fractional or Decimal? A Beginners' Guide to Fixed-Odds Betting

One of the most confusing aspects for any person new to gambling has always been the way that horse racing odds for each runner in a race are presented. Unfortunately, this situation has become even less clear-cut over the past few years, particularly for the novice punter who has chosen to gamble using the Internet.

Traditionally, British bookmakers would always present their odds in a fractional format, and this is still in widespread use across the UK, in betting shops, online and with on course bookmakers. Therefore, for example, the favourite for the 2011 Grand National at the time of writing is The Midnight Club, with odds of around 12/1.

If you back a horse to win at these odds, this would mean that whatever stake you gamble on the horse winning the race, you will receive 12 times that amount back, plus your original stake should the horse win. So, if The Midnight Club romps home in the big race at Aintree in April and you have placed a £10 bet on the horse to win, then you will receive £120 in winnings, plus your original £10 stake, for a total return of £130.

While most UK punters have at least a basic understanding of this odds system, problems arise when they log into their chosen bookmaking account online and see odds not presented in a fractional format but instead based on the decimal system, which is in widespread use across Europe and Asia.

Fortunately, understanding the decimal system, if used by an online bookmaker is not difficult. In decimal odds, 2.00 is the even money mark and there is a logic behind this. An even money favourite will mean you double your stake. Therefore, you can view the decimal odds as simply being your total winnings from the race. Therefore, in this example, if you wager £10 on a horse at 2.00, you will receive £20 back in total, £10 winnings and your £10 stake returned.

So, in our example of the Grand National favourite The Midnight Club, the decimal presentation of his current odds of 12/1 would be 13.00.

Decimal odds become more complicated for the beginner punter to understand when a horse is odds on to win that is below even money. Despite that, the logic applied earlier still follows. A horse that is a 1/3 favourite is shown in decimal odds as 1.33. This means that if the horse wins, the punter will receive their stake back, plus 33 per cent of the stake as winnings.

A horse that is a very well-backed favourite to win, say at fractional odds of 1/10, would be written as 1.10 in decimal odds, meaning that if the horse wins, the punter will receive back their stake, plus one tenth of the stake in winnings.

New punters need not worry about decimal odds as most online bookmakers offer the ability to have the odds presented in either format, but it is good practice to have an understanding of the odds on offer, in any format, before you make a bet. After all, everybody would like to know what they could win, should his or her horse emerge victorious.