The evolution of exchange betting has revolutionised market-making to such a degree that even the biggest bookmaker names no longer employ professional odds setters.

1. Bet Odds Calculator
2. Understand Betting Odds

How did odds making start?

As touched on in our Brief History of Betting blog, the concept of calculating the likely chance of a winner in a horse race, and converting that into bookmaker odds, was devised by one Harry Ogden.

Luckily, they’re very straightforward and easy to calculate. All you have to do is multiply your wager by the odds to find out your potential winnings. Bet x Odds = Payout (original bet + profit) For example, if you bet $100 on a team winning, with odds at 1.82, then your potential total amount received is $182. In sports betting, each team is assigned odds that represent the likelihood of them winning the game. When the odds for two teams are even, meaning 1 to 1, it means that each team is equally as likely to win the game. If Team A is assigned 2 to 1 odds, it means Team B is twice as likely to win. The VegasInsider.com Sports Betting 101 Odds feature is your ultimate resource to understanding 'How to Read Odds.' Once you understand the odds, then you'll be more prepared to make a bet and more importantly, win your bet! Odds are easy to understand but there are different formats and once you become familiar with all of them, you can choose your preference. Although some people find decimals an easier way to view the equation, it is really a personal preference. The equation to determine betting odd probabilities with decimals is: your winnings = (odd. stake). For example: 4.0 can be calculated as (4.0. $10 stake) = $40 in winnings. If you are planning to enter the betting or the gambling world, it is important to understand and interpret all types of odds well. Be it casino gambling, sports betting, or any other type, it’s important to understand the odds.

Operating on Newmarket Heath towards the end of the 18th century, Ogden was the first bookmaker to take betting beyond its strikingly crude roots. Most early bets were simply a way of settling an argument over whether a named event would come to pass or not.

Not only did Ogden begin the process of making a book, he also understood that he had to save a percentage of his takings for his own purse. In order to achieve this, he slightly adjusted prices in his favour. It worked: if somebody won a bet and got paid out at odds of 4/1 they were unlikely to complain, especially at this early stage, that they had not been paid at the true probability of 5/1.

So already, within Ogden’s lifetime we witnessed the evolution of a book featuring a range of prices as well as the concept of what is now known as an “overround”.

What is an overround book?

A perfect book, without factoring in a margin for the bookie, would mean the implied probability of all outcomes would add up to 100%. However, bookies use the concept of overround to stretch this probability greater than 100% – which then becomes their profit.

Here’s an overround example from a tennis match:

Now, have you ever considered why bookmakers like to encourage accumulators in sports like football where punters enjoy backing multiple selections in a single bet?

Well it’s simple: if a bookmaker has an overround of 105% on each of five football matches, a punter placing a bet in all five of those matches is betting against an overround 125% because the extra 5% is factored in each time.

The growth of betting and odds compiling

By the 1950s the big firms that covered the length and breadth of the country betting on horses and greyhounds were already employing odds-makers to help them compile what was known as the “tissue” for each race.

This was effectively the first show of prices. Bookmakers would certainly collude to some degree to check their assessments of the market were not wildly out of place but by and large they were happy to trust their instincts.

The prices were not static: they moved to respond to market forces after the first show was published on the boards.

What did a bookie do if he felt liabilities were in danger of getting too big on a particular horse? All he had to do was rub off the displayed price on his chalkboard and put up a less attractive price. He might then balance his book by pushing out the prices of less fancied runners.

The advent of legal betting shops

The golden age of betting was triggered by the 1960 Betting and Gaming Act – a watershed development that allowed betting on racing and greyhounds to take place in licensed shops around the country.

For the first time, punters did not need to be physically at a racecourse or dog track to legally place a bet. There was still an incentive for big-time punters to go racing because if they were betting in shops they had to pay tax.

But bookmakers small and large had to be on the lookout to protect themselves against betting coups in what was now “open season” for big-stakes punters. If, for example, a group of individuals could target multiple betting shops at the same time soon before the start of a race it was hard in the pre-internet age to ensure the price was cut in time.

The Yellow Sam plot of 1975 was a perfect illustration of how a meticulously organised plot could evade the best attempts of the bookies to minimise their exposure.

The 1990s: Multiple sports, multiple platforms

When restrictions were lifted on football betting to unlock a wide range of markets on individual matches, horse racing’s dominance as a sports betting medium was challenged for the first time.

At the same time, firms were opening more and more shops, allowing telephone and online accounts while accessing more and more global television feeds.

This was the decade in which odds-compilers really earned their corn for bookies like Coral, Ladbrokes and William Hill – traditional names with presence on the high-street, at the courses and, bit by bit, on rudimentary web browsers too.

Sports traders and palps

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If, for example, you were a graduate with a good degree in maths or economics and you also followed rugby union religiously you could be hired specifically to draw up rugby union markets for one of the big operators.

With so much sport to bet on, and so many new avenues from which to glean useful information, this was also the time that “palps” (bookie slang for palpable errors) were at their most prevalent.

Shrewd punters could sometimes find out if an obscure tennis match or an overseas domestic football game had been rescheduled to an earlier time slot. If the bookies were unaware they could find themselves accepting a bet on an event that had already happened.

How exchanges changed the landscape

The arrival of Betfair into an increasingly cluttered market in 2000 proved a positive intervention in a number of ways, even if some small on-course bookmakers to this day rue the dawn of exchange betting.

Betfair had a huge USP: it was allowing markets to be set by individuals trading on its platforms hours and sometimes days in advance. The prices were not set by individual odds-makers using personal assessment.

Over the intervening 20 years, the exchanges have had their ups and downs but for bookmakers they provide two major positives which serve as some sort of compensation for draining them of the business they once did.

Firstly, by using the wisdom of the crowd, exchanges establish robust markets relatively quickly meaning betting companies no longer need to invest so heavily in their own odds-makers.

Secondly, the exchanges provide an easy mechanism for bookmakers to lay off worrying liabilities and can even provide early warning of a potential betting coup attempt.

What is BetConnect’s role in the market?

BetConnect is a hybrid solution that combines many of the strengths of the Betfair model – it is, after all, a peer-to-peer exchange – alongside the reassurance of big bets being matched without restrictions.

Available prices quoted are based on real-time markets provided by a wide range of online bookmakers. The platform gives bettors reassurance that they are getting the best bookie prices while layers know where to head for matched betting opportunities.

BetConnect’s single biggest advantage is its ability to fuse three disparate groups of individuals:

1. Professional punters who have grown frustrated by restrictions imposed on them by the bookies
2. Recreational players who enjoy backing and laying selections
3. The growing community of matched betting enthusiasts

If you think you’re ready to bet on horse racing or any other sport then sign up for a BetConnect account now. BetConnect is the only exchange that lets you back selections at bookie odds with no restrictions, and lay the selections of other account-holders commission-free. Not sure how it works? Read this simple guide.

related

• Betting odds tell you how likely an event is to happen
• They also tell you how much money you will win
• However, at first, they may seem confusing and complex
• Our comprehensive guide takes you step-by-step to explain them

If you’re new to betting, one of the first things you should do is learn how betting odds work. It’s critically important because it allows you to understand how likely an event is to happen, and what your potential winnings will be. At first, it may appear confusing, however, read our guide and let us explain it to you.

In gambling, odds represent the ratio between the amounts staked by parties to a wager or bet. Thus, odds of 3 to 1 mean the first party (the bookmaker) stakes three times the amount staked by the second party (the bettor).

What is Probability?

Understand Betting Odds

The most basic level, betting provides you with the ability to predict the outcome of a certain event, and if your prediction is correct, you will win money. For any given event, there are a certain number of outcomes. Take rolling a dice for instance. If someone rolls a dice, there are six possible outcomes. Therefore, if you bet that the person rolls a ‘one’, there is a 16.67% chance that will happen. What betting odds merely do is present how likely the event is to happen. Bookies most frequently in the UK do this as a fraction, i.e. 4/7, whilst the vast majority also offer the ability to view them as decimals. Again, let us talk you through them. All will become clear.

Using Betting Odds to Calculate Probability

Whenever you see two numbers separated by a trailing slash, i.e. 10/1, this is known as fractional odds. From this, you can calculate how likely a given event is to happen with a calculation. For ease of explanation, let’s replace the numbers with letters i.e. 4/1 becomes A/B. Here is the calculation: Probability (%) = B / (A+B).

• 9/1 can be calculated as 1 / (9 + 1) = 0.10– There is a 10% chance that the event will happen.
• 4/1 can be calculated as 1 / (4 + 1) = 0.20 – There is a 20% chance that the event will happen.
• 1/1 can be calculated as 1 / (1 + 1) = 0.50 – There is a 50% chance that the event will happen.
• 1/4 can be calculated as 4 / (4 + 1) = 0.80 – There is a 80% chance that the event will happen.

Hooray! We’re making progress. Given a fraction, we can now tell how likely (the probability) what we’re going to bet on will happen. Now let’s figure out how much money can be won using betting odds.

Using Betting Odds to Calculate Winnings

Betting odds allow you to calculate how much money you will win if you make a bet. Let’s use the same examples as before, with the same replacement of numbers for letters, i.e. 4/1 becomes A/B. Quite simply, for every value of B that you bet, you will win A, plus the return of your stake.

• 9/1 for every £1 you bet, you will win £9.
• 4/1 for every £1 you bet, you will win £4.
• 1/1 for every £1 you bet, you will win £1.
• 1/4 for every £4 you bet, you will win £1.

What About Decimals?

Decimals are far more common on exchanges, such as Betfair, but all leading betting sites do give you the option to view betting odds in this format. They are an alternative to seeing betting odds in the fraction format, and in our opinion, are easier to work out. Here is the calculation: winnings = (odds * stake) – stake. Let’s illustrate it with some examples

• 9.0 can be calculated as (9.0 * £10 stake) – £10 stake = £80 winnings.
• 4.0 can be calculated as (4.0 * £10 stake) – £10 stake = £30 winnings.
• 2.5 can be calculated as (2.5 * £10 stake) – £10 stake = £15 winnings.
• 1.25 can be calculated as (1.25 * £10 stake) – £10 stake =£2.50 winnings.

You can use our bet calculator to help you calculate winnings.
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Decimal Odds Versus Fractional Odds

In truth, one isn’t better than the other but there is certainly a trend emerging towards decimal odds. Historically fractional odds were used in the UK, especially on racetracks and on the high street. There are two key differences. Generally, decimal odds are easier to understand. Based on this, there has a movement to attract more people to horse racing by making it more accessible to the average punter. Ten years ago, if you were going to Cheltenham, all the odds would be displayed as fractional odds. Now, they’re largely all in decimals. Don’t hesitate to check out our exclusive Premier League Betting Offers !

The second difference between the formats is that fractional odds only represent winnings, and do not include the returned stake compared to decimals which do include the stake. The transition from fractional odds to decimals largely kicked off with the growing popularity of the betting exchanges such Betfair. For odds to change slightly, it’s really difficult to marginally increase or decrease the probability without creating large fractions which are hard to compute for the punter.

Use Our Tool to Convert Betting Odds Into Your Favourite Format

Our odds converter toolwill allow you see odds in whatever format you like . Not only that, but it’ll tell you how likely the selection is to win!

In Summary

Betting odds represent the probability of an event to happen and therefore enable you to work out how much money you will win if your bet wins. As an example, with odds of 4/1, for every £1 you bet, you will win £4. There is a 20% chance of this happening, calculated by 1 / (4 + 1) = 0.20.

Next steps

That’s it! Hopefully, that clears up betting odds. You should now have the knowledge to read betting odds, understand how likely it is to happen, and how much you stand to win.

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