Decimal odds are essential to modern betting, and that’s because decimal odds tell the person placing a bet how much they will receive if their bet succeeds. The decimal odds used in the betting world usually include the returned stake for a winning bet, so decimal odds of 2.00 would double the stake of the person betting. A winning bet of £50 at decimal odds of 2.00 would therefore result in the bettor receiving £100.
Before decimal odds were introduced, fractional odds were used to convey the same basic information (the payoff for a winning bet) but in a more complicated form. For example, odds of 13/8 told the bettor that a winning £10 bet would make a profit of £16.25. Unfortunately, for the bettor to make the link between fractional odds of 13/8 and the £16.25 profit figure, he would first need to know how to use them (the answer is to divide the left hand side of the odds by the right hand side and multiply by the stake). Those who didn’t know how fractional odds worked were therefore very much ‘in the dark’ about what the figures actually represented.
Decimal odds are easier
This illustrates quite clearly how much easier decimal odds are to understand and work with on a practical level. Whilst oldfashioned fractional odds may be steeped in tradition and regarded with a certain amount of sentimentality by some, the simple fact is that they are far too complicated for the digital age. Decimal odds, by comparison, are clean and straightforward and even those who are brand new to betting can easily get to grips with them,
Fractional odds
Before decimal odds were introduced to the sports betting world, fractional odds were used to tell bettors how much profit they would make from a winning bet. Fractional odds consist of two numbers with a dividing line between them, and when discussing them in spoken communication the dividing line is usually replaced with the word 'to'. Odds of 11/8 and 4/5 would therefore be spoken as 'eleven to eight' and 'four to five', respectively.
The number on the left hand side of the fractional odds dividing line represents the profit that a bettor will make if he bets the number on the right hand side. Fractional odds of 11/8 therefore means that the bettor would make a profit of £11 for every £8 bet. This scenario, where the potential profit is larger than the size of the bet, is described as 'odds against'. Odds of 4/5 would mean that the bettor would make a profit of £4 for every £5 bet, and because the potential profit is smaller than the size of the bet, the situation is sometimes described as 'odds on'.
As you will have noted from the explanation given a moment ago, fractional odds represent potential profits only, and not the total return that the bettor would receive from a winning bet. It is therefore important to add in the fact that the stake of the original bet is returned to the winner as well as the profit element.
For example, if you were to place a winning £10 bet on a horse at fractional odds of 7/2, you would make £35 profit and your £10 stake would also be returned to you, giving you a total return of £45. This much is obvious to those who are familiar with fractional odds, but for those who are new to the subject it is not so obvious, and many people have at some point wondered why anyone would bet on a 2/5 shot where the potential profit is just £2 for every £5 bet. Add in the fact that the £5 stake is also returned to the bettor and the bet suddenly makes a lot more sense!
Fractional odds have always played a much more important role in the UK than they have in other countries (where decimal odds have been in use for some time) and so it isn't surprising that many phrases relating to fractional odds have crept into common usage in the UK. For example, when an outcome is described as being 'odds on' to take place, the person is saying that it is more likely to happen than not. Similarly, when there is said to be an 'even Stevens' chance of something happening, then this refers to fractional odds of 1/1, meaning that the situation could go either way.
Although fractional odds served their purpose well in the days of imperial measurements, and will therefore be remembered with fondness by many, decimal odds are much better suited to the current metric system, and are definitely a lot more userfriendly.
