It goes without saying that the odds are a fundamental of any type of betting, and knowledge of what they mean and how they work is crucial in helping you to plan your bets correctly.

In the following article we introduce the basics of how odds work and show you how odds can compound in dramatic style in accumulators. We’ll also help you understand how decimal odds work as well as the more traditional fractions.

Odds 101 – An Introduction

Odds represent the likelihood of a particular outcome, such as Horse X winning its race, and dictate how much money you will win if your bet is successful. They are traditionally shown as fractions (e.g 2/1 or 4/1) and are quite easy to get your head around, even if maths was never your strong point.

Fractional odds are easy to understand if you use the basic rule that the number on the right represents your stake and the number on the left represents the amount you will win to that stake. To make it even simpler, let’s use 2/1, 4/1, 9/1 and 11/2 as examples:

2/1 – The number on the right (1) is your £1 stake. The number on the left (2) is the amount you will win to that £1 – so a 2/1 bet will return £2 winnings to every £1 staked (plus you will get your stake back, so £3 in your hand).

4/1 – Same principle, but this time you will win £4 to every £1 staked.

9/1 – £9 winnings for every £1 staked.

11/2 – OK, the 1 on the right has been replaced by a 2. In fractional odds only whole numbers are used, so instead of offering odds of 5.5/1 a bookmaker offers 11/2 instead. The same principle applies, but the odds show your return from a £2 stake instead. So 11/2 means you will win £11 for every £2 staked. If you want to understand these odds against a £1 stake then halve the two numbers, which means £5.50 to every £1 staked.

Still with me?

If you like to think of the probability of something happening in percentages, then you can convert odds into a % possibility. If a horse is priced at 4/1 then it is considered to have a 20% chance of winning, and an 80% of NOT winning. A horse at 9/1 is believed to have a 10% chance of winning, and a 90% chance of NOT winning.

As you either know or can assume already, the better the horse and the more suitable the conditions of the race then the better the chances of winning that the horse has – therefore the odds will be lower than the odds offered for a horse that has a terrible track record (known as ‘form’) running in a race that it is unsuited for. A horse that is believed to be far, far better than its rivals in a race can often have odds that are so low that they are known as ‘odds on’.

‘Odds On’ simply means that you will win less that your stake if your horse wins. For example, the favourite in a race is believed to be unstoppable (take Frankel as a recent example), and bookmakers don’t want to be paying out too much money if that horse wins, so the horse gets priced odds on at 1/5. Same rule applies to the numbers in that the number on the right (5) is your stake, and the left is your winnings to that stake. So, a 1/5 favourite means you will only win £1 for every £5 you stake. You’d need to stake £50 to win £10. But what if this is the race where the superhorse meets its match….a big stake to risk for such little possible returns.
Understand that the odds offered represent the likelihood of something happening. Yes, a 100/1 horse can win you £100 for every £1 you bet, but it is perceived to have only a 0.99% chance of winning. Use your head with every bet and try not to give away your hard earned cash to bookmakers by backing ‘dreams’ such as these.

The way that odds compound mean that you can have a better chance of winning big with a small stake if you place accumulator bets.

Odds & Accumulators

OK, you want to try and win £100. Well, backing that 100/1 horse just isn’t going to work….or it might only work 1 out of every 100 times you try it if all things were equal (which they aren’t).

If you see a horse priced at Evens (1/1) then you’ll have to bet £100 to win £100….risky. One way to try it might be to use the weight of how odds compound and back 3 horses to win in a Treble. If you have done your homework, and you can see 3 horses you fancy on any given day, at odds of 2/1, 6/1 and 4/1 respectively then a winning £1 treble will return £105 including your £1 stake.

How does that work???

Ok, you need all 3 horses to win, so it’s already going to be a long shot (but in my view not as long as 100/1 horse winning) – you place your £1 treble and watch the races. The first horse wins at 2/1 so you now have £3 riding on the 6/1 horse in the second race. This £3 is your £2 winnings plus your £1 stake. Your 6/1 horse wins, so you now have £21 (£18 winnings plus £3 stake) going on the 3rd horse at 4/1. This horse wins, and you trot to the bookmaker’s window to collect £105 (£104 winnings plus your £1 stake back).

Decimal Odds Explained

More recently, and especially with the growth in popularity of online bookmakers (especially Betfair), decimal odds are being used more and more. Usually in a bookmakers shop you will see fractional odds on display, but an understanding of decimals is useful so that you know what you are doing the next time you come across them.

Decimals represent the amount of the return you will receive from your stake and include the stake itself. An Evens bet where you will win £1 for every £1 stake you place is shown in decimal odds as 2.0. A 4/1 bet where you will win £4 for every £1 you stake is shown as 5.0.

To quickly work out the winnings from a decimal odds bet, simply take 1 away from the decimal odds value and multiply the remainder by your stake. The 1 you take away is the value of your stake. So, if you see decimal odds of 10.0 then take 1 away (stake) and you have 9.0, so your winnings would be £9 if your stake was £1 and £90 if your stake was £10.

Odds on values in decimals are any value less than 2.0. A bet at 1.75 decimal odds will return 75p winnings to a £1 stake, plus your stake returned (£1.75 given back per £1 bet).