Sports odds, whether you’re in a land-based casino or reading your favorite online sportsbook, are always heavily influenced by what’s coming out of Sin City as they generally have the last word. Understanding sports betting is integral for beginners and here we will provide a comprehensive understanding of all that encompasses betting odds. Understanding the world of online betting can be a daunting task for the sports betting novice. You’re met with a wall of numbers, dots and dashes before you even get started. The key to enjoyable betting is in knowing how to read the odds.

Understanding Sports Odds
by Trevor Whenham - 05/08/2008

Here's the most simplistic but true statement I can possibly make about sports betting - understanding sports odds is a pretty important part of sports betting. You can be the best handicapper in the world, and you can pick winners with shocking regularity, but if you don't understand odds then you can't know if a bet is worth making, and you probably won't be a winner in the end. Fortunately, understanding sports odds isn't that tough once you figure it all out.

Before we look at the details of things there is one thing to keep in mind - your job as a sports bettor is to determine what you think the likelihood of something happening is and then to compare it to the odds of that event occurring. If the posted odds are better than your anticipated likelihood then you have a bet worth making, but if the odds, or the potential return on the bet, is less than the chances you give the bet of being successful then it is not worthwhile. Novice or unsuccessful bettors think that sports betting is all about picking winners, but that is only a small part of success.

There are a number of different ways that odds can be presented, but they all come down to the same thing. Sports books assign what they think is a fair price for a particular outcome. By fair price I mean that the books try to set a price that is attractive to bettors so that they will bet on it, but not so attractive that they will get too many bets and risk losing money. Books will adjust the odds once they have been set if they are attracting too much or too little action.

Sports odds can be presented in a number of different ways, but they all represent the same thing in one way or another - the amount you will win if you make a bet and are correct. They express them in different ways, but that's the meaning.

Fractional odds - These aren't the most common in sports betting, but they are the easiest to understand so we will start here. They are used in horse racing, so if you are familiar with betting on the ponies then you know fractional odds. Not surprisingly, they are expressed as a fraction. For example, odds of 4/1 mean that you would win four dollars if you bet one dollar and were correct. The odds can be less than even, too. Odds of 1/4 would mean that you would have to bet four dollars to win one dollar. With fractional odds it is also quite simple to figure out if a bet makes sense. If the odds are 4/1 and you think that something is likely to happen once in three tries then it is a very profitable bet. On the other hand, if it were likely to happen once every five tries then you would lose money in the long term if you bet it at 4/1.

Decimal odds - These aren't used in the United States very often, but they are seen in Canada, Europe and Australia. They can also be the most confusing at first. The easiest way to understand them is to start with fractional odds. To make a conversion you take the fraction, turn it into a decimal, and add one. That means that 4/1 fractional odds would convert to decimal odds of five, and 1/4 odds would become 1.25.

Money line odds - These are by far the most common form of odds in North America for sports betting. They are expressed as numbers greater than 100, and they can be either a positive or negative number. Each one is a little bit different.

When a money line is a positive number then the odds are the amount you would win if you were to bet $100 and were correct. For example, a money line of +200 would mean that you would make a profit of $200 if you bet $100 and were correct. That's also equivalent to fractional odds of 2/1 and decimal odds of 3.

A negative money line represents the amount that you would have to bet to win $100 if you were correct. For example, a -200 money line means you would win $100 if you bet $200 and won. It is also equivalent to fractional odds of 1/2 and decimal odds of 1.5.

• 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?

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.

Understanding Odds Ratio In Sports

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.
USE BET CALCULATOR

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 !

Understanding Odds In Sports Betting

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

Sports Odds Explained

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.

How To Understand Sports Betting

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