How Do Betting Odds Work? - Detailed Betting Odds Explained

If you’re looking to learn more about how betting odds work, this detailed guide is for you. Having decent knowledge of how betting odds operate is crucial to not only play successfully - but also enjoy your betting experiences to the full. In simple terms, betting odds display how likely a particular outcome will happen, as determined by bookmakers. However, getting clear answers for how betting odds work isn’t a walk in the park, and can confuse a lot of new players. This full guide provides you with all you need to know to interpret and understand betting odds ahead of your next bet.

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Betting Sites With the Best Odds

22Bet

Featuring a huge range of sporting categories and excellent customer support, 22Bet is the perfect choice if variety is top of your list. 22Bet also has one of the highest-quality betting apps out there, available for download on both iOS and Android devices.
New players will also receive a 100% match bonus after creating an account. Available up to the value of €122, simply meet the minimum deposit requirements and you can claim this promotion before you start betting.

ProsCons
High-quality mobile appLimited live streaming options
Regular varied promotionsOnly 6 payment methods available
Over 40 sporting categories
Live sport statistics

BetVictor

BetVictor

BetVictor is extremely user-friendly and offers some of the fastest payment and withdrawal times within the online betting scene. You’ll also find an ‘Odds Guarantee’ when playing here, meaning you can be rest assured the odds you’re receiving are as competitive as possible.
You’ll also find a great customer support team here, available via live chat, email and phone 24 hours a day, 7 days a week.

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Competitive odds across all sportsLimited live streaming options
Industry-leading horse racing coverageDownloadable app isn’t the best
Wide range of betting markets
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LeoVegas

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If you’re into online casino games, there’s a strong chance you’ll have already heard of LeoVegas. However, this site offers equally good sports betting opportunities, making it one of the most comprehensive sites out there.
You’ll find an impressive sportsbook as well as a range of regular bonuses for loyal players. Many sports are streamed live for a more immersive experience, and we were particularly impressed with the LeoVegas horse racing coverage.

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Novibet

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Novibet has already made an impressive name for itself since launching on the scene back in 2021. Featuring up-to-date sports statistics as well as competitive odds, you’ll have all you need to make informed betting decisions when playing here.
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30 sports categoriesNo live streaming options
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Betinia

Betinia

With over 30 sports categories available here, it’s safe to say you won’t ever get bored betting at Betinia. Able to cater to virtually any taste and featuring great live in-play betting options, there’s a lot to sink your teeth into – as well as impressive bonuses specific to different sports.
However, if you’re a horse racing or greyhound racing fan, Betinia may not be for you. They are yet to add these markets to their sportsbook.

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What Are Betting Odds?

Odds in betting are specific odds based on the likelihood of a particular outcome happening. Betting odds are determined by bookmakers responsible for whichever site or establishment you’re betting with.
For example, if you placed a bet with odds of 6/1, bookmakers will stake six times the amount you have wagered. If you successfully win, you will receive six times your original bet. So, if you wagered €1, you would receive €7 back as a result of the betting odds. This includes your original stake of €1, plus your total profit of €6.

The Importance of Having Betting Odds Explained

Especially if you’re new to Irish online betting, you’ve probably asked ‘how do betting odds work?’ plenty of times. And for good reason! Understanding how to interpret and read betting odds couldn’t be more important when you’re playing with real funds.
Having betting odds explained will give you greater insight into where best to place your bets, allowing you to make a better-informed decision on how much of a risk you want to take. Without this information, it would be virtually impossible for you to make a knowledgeable and rational betting choice.

Calculating Probability From Odds

The first key step in learning how betting odds work is understanding how to calculate probability. One of the most common odds format types you’ll see is ‘4/1’, two figures separated by a slash. These are referred to as fractional odds and, when read correctly, will allow you to calculate the probability of an event.
One of the best ways to interpret this is with a simple formula: Probability = second figure / (first figure + second figure). Here are some examples to demonstrate this betting odds concept more clearly:

  • 4/1 is calculated via 1 / (4+1) = 0.2. This means there is a 20% chance the event will occur.
  • 1/4 is calculated via 4 (1+4) = 0.8. This means there is an 80% chance the event will occur.
  • 7/1 is calculated via 1 / (7+1) = 0.125. This means there is a 12.5% chance the event will occur.

How to Read Different Types of Betting Odds

While we’ve just discussed fractional odds when looking to calculate probability, there are multiple types of odds format you may be faced with. When looking at how betting odds work, having an understanding of these different types is crucial.
In this guide, we will cover fractional odds in more detail, as well as decimal odds and American odds (also known as moneyline odds).

Fractional Odds

A major part of understanding betting odds is converting them to implied probability, which we’ve already demonstrated. However, there are more methods to read betting odds that are definitely worth becoming familiar with, such as fractional odds.
Fractional odds are typically considered one of the easiest sports betting formats to understand. To reinforce their simplicity, here are some quick examples of both ‘odds on’, ‘evens’ and ‘odds against’ types:

  • 8/1 – Bookmakers will pay €8 for every €1 you wager
  • 13/2 – Bookmakers will pay €13 for every €2 you wager
  • 1/1 – Bookmakers will pay €1 for every €1 you wager
  • 4/6 – Bookmakers will pay €4 for every €5 you wager

To explain betting odds further, the first two bets in this list are referred to as ‘odds against’. This means that bookmakers don’t think the probability of an event is very high i.e. they don’t think it’s very likely to occur.
The third example is known as an ‘evens’ scenario, meaning your wager will be doubled if you win. Lastly, the final example in the list is an ‘odds on’ situation, representing the opposite of ‘odds against’. This is when bookmakers predict an event is highly likely to occur.
Many betting odds will often be presented as percentages, giving a clearer indication of potential profit. For example, fractional odds of 4/1 represent a 400% profit, in addition to 100% of the money you originally wagered. If you place a bet of €10, you would receive €50 back in total.

Decimal Odds

In addition to fractional odds, decimal odds are a pretty commonly-used bettings odds format. As the name suggests, decimal odds utilise a decimal arrangement to help players calculate implied probability.
In fact, decimal odds are typically considered easier to interpret at a quick glance than fractional odds. The higher the number, the greater your potential profits. Some decimal examples are as follows:

  • 6.00 = wager €1, receive €6 back
  • 6.00 = wager €6, receive €36 back
  • 3.00 = wager €4, receive €12 back (applicable to 1/1 events)

If you’re looking to convert decimal odds to a percentage, simply multiply the specific decimal by 100 to get your percentage figure. For example, 1.40 works out to 140% of the amount wagered. To demonstrate how do odds work in betting percentages, see below:

  • You wager €10 at 1.40 decimal odds
  • 1.40 multiplied by 100 is 140%
  • €10 multiplied by 140% is €14
  • This figure of €14 means you’ll receive 140% of your original stake back, provided your bet is successful

To confirm the odds explained, it’s important to understand how to convert decimal betting odds to actual probability. This is achieved by considering the value of the decimal itself. For example, betting odds of 2.0 represent a 50% chance of a successful win. Therefore, odds less than 2.0 will have a greater opportunity. of winning, and odds above will deliver a lower chance.

American Moneyline Odds

Whether referred to as American odds or moneyline odds, they mean the same thing for this betting odds type. As the name suggests, American odds are most commonly seen in betting establishments in the US. But, for the purposes of how to read betting odds, it’s important to understand multiple types fully.
American odds can feature either a positive or negative number. A positive number signals an ‘underdog’ scenario, showcasing how much of a profit you’ll gain with a €100 wager. Alternatively, a ‘favourites’ situation demonstrates how much you need to wager to gain a €100 profit.
To put moneyline odds into action, here are a few examples:

  • +150 means that, if you wager €100, you’ll win €150. This will result in an overall profit of €250.
  • +150 with a €10 wager will give you a win of €15, resulting in an overall profit of €25.
  • -175 means that, if you wager €175, you’ll win €75. This will result in an overall loss of €100.

To convert American odds, whether they fall as ‘underdogs’ or ‘favourites’ must be taken into account.
Underdog odds represent a profit, meaning that the percentage is calculated using the odds + 100% of the specific wager. This method can be used to establish what you’ll gain should your bet be successful. For example, if you’re working with moneyline odds of +150, this equates to 150%.
Favourites are slightly different. A foolproof method to convert betting odds of this type is this equation: 100 – (10,000/odds).

Betting Odds Conversion

Whether you prefer fractional odds, decimal odds or American odds, you can’t always choose how they’re presented to you. This means it’s essential to be able to convert whichever odds you’re faced with to a type you are more familiar with, enabling you to have an easier and more enjoyable betting experience.
To get a better idea of what betting odds conversions look like with some commonly-seen odds, see the table below:

Fractional oddsDecimal oddsAmerican oddsImplied probability
1/1001.01-10,00099%
1/41.25-40080%
1/51.2-50083.3%
1/31.33-30075%
2/101.2-50083.3%
2/71.29-35077.8%

Converting Decimal Odds to Fractional Odds (and Vice Versa)

Turning decimal odds into fractional odds is one of the most common forms of betting odds conversions – especially in Ireland.
To successfully complete this conversion, we recommend using this simple formula:
If the fractional odds are 1/4 then this requires (4 / 1 + 1.0).
Using this specific example, the formula is as follows:
(4 / 1) + 1.0 = 6.0.
With straightforward fractional odds, this formula is very easy to master. Even when faced with more complicated odds, you should still get the hang of it with a little practice. For example, let’s take 2/7:
(7 / 2) + 1.0 = 4.5.
Converting fractional odds to decimal odds is equally simple. Let’s take 5.00 odds as an example, using the formula (x – 1.00) / 1:
5.00 – 1.00 = 4.00 = 4/1.

Converting American Odds to Decimal Odds (and Vice Versa)

As mentioned, American moneyline odds will either be an ‘underdog’ or a ‘favourite’. The formula you use to convert these betting odds will depend on the type of odd in question.
When dealing with underdog American odds, we recommend using the equation (+x / 100) +1. For example, if handling +300 moneyline odds, the formula would be:
(300 / 100) +1 = 4.00.
Favourite odds require a slightly different process. Instead of dividing the odd amount by 100, it is vice versa. So, for -300 odds, the formula is:
(100 / 300) +1 = 1.33.
When converting the opposite way, the equation you’ll use solely depends on the decimal value in question. For decimal odds at 2.00 or higher, use (decimal odds – 1) x 100. But, for decimal odds lower than 2.00, -100 / (decimal odds – 1) should be used instead.

Converting Fractional Odds to American Odds (and Vice Versa)

In a similar way to other conversions we’ve already discussed, to convert fractional odds to American odds the formula will be determined by the fraction value. For fractions higher than one, you should use the equation (x / y ) x 100; for fractions lower than one, you should use -100 (x / y) instead. Let’s use 4/1 as our first example:
(4 / 1) x 100 = 400.
For fractions lower than one, we’ll use 2/7:
-100 / (2 / 7) = -350.
When converting American odds to fractional odds, the same rule applies as earlier examples. The formula you use will depend on whether the moneyline odd is an ‘underdog’ or a ‘favourite’.
Underdog American odds require the formula x / 100 – and simplification of the fraction if necessary. So, for +500 American odds:
500 / 100 = 5/1.
Converting favourite odds is a little more complicated, but should be easy to master with practice. Let’s take -400 American odds as our example, with the formula -100 / x:
-100 / -400
0.25/1 * 1000/1000 = 250/1000.

Live Betting Odds

Caxino CasinoAlso known as in-play betting, live betting odds often add an extra layer to a player’s betting experience. Live betting odds are odds that are determined in real-time by bookmakers. They heavily take into account what is currently happening during the event in question, and can even accommodate previous results or similar situations that have occurred previously.
For this reason, live betting odds are unpredictable and can dramatically change as an event unfolds. All aspects of what is happening in real-time are taken into consideration by the bookmakers, to deliver the most accurate betting odds possible.

Odds on Popular Betting Markets

Different betting markets will have different types of possible bets. Here are some of the most popular types of bets players can make on some top sports enjoyed worldwide.

  • Football betting odds: One of the most popular football betting types are focused on a specific score at the end of the game. Other commonly-seen bets are half time/full time results (HT/FT), first goal scorer (FGS) and total goals (under/over).
  • Horse racing betting odds: Horse racing is one of the most popular sports people bet on across the globe. Common bets include Quinella (which horses will come first or seconds), Trifecta (specific order of first, second and third), and a straight up win.
  • Boxing betting odds: Boxing features a variety of different bets, each with their own intricacies. Players can make round-specific bets, as well as how a boxer wins (KO, decision etc.) or simply predicting the overall winner.
  • Golf betting odds: The simplest golfing bet is overall tournament winner. Other betting options include specific finishing positions, head-to-head matchups and each-way bets.
  • Tennis betting odds: Common tennis betting types include set betting (predicting exact scores per set for a particular player), total games played throughout the match, and number of tie breakers.

Responsible Betting

As with any form of gambling, whether odds sports betting or playing at online casinos, responsible wagering is absolutely crucial. Betting addiction is something that many individuals fall victim to, making responsible gambling policies an aspect all reputable betting establishments and websites should provide.
If you find yourself constantly thinking about betting and struggling to do other things, it’s highly recommended to take a break and seek advice. All licensed betting services will have a customer support team on-hand to talk to if you need help, and many gambling websites offer a range of options to pause your account for certain periods of time.

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FAQ

Is it legal to bet on sports in Ireland?
Yes, it is completely legal to place bets on sports in Ireland provided you’re betting at a licensed establishment. Always check the terms and conditions of wherever you’re betting at, and walk away if something doesn’t seem right.
What do odds represent in betting?
Odds represent the likelihood that a specific event will occur or not, and are established by expert bookmakers. Understanding betting odds is crucial to ensure you’re making an informed decision on potential risks - and how much you want to bet.
How can I convert odds from one format to another?
This guide details how to convert odds across three different formats: fractional odds, decimal odds, and American moneyline odds. Some conversions are easier than others but, with time and practice, conversions should be relatively straightforward.
Are there any foolproof betting strategies?
No, there are currently no foolproof strategies that will guarantee successful bets. A huge element of betting is risk, which reinforces the importance of understanding betting odds and knowing how to interpret them in line with your financial situation.
How do I know if odds have value?
Calculating probability is a huge part of understanding whether odds have genuine value that aligns with your goals. If the return you’re expecting is profitable and holds value in your opinion, then it would be fair to assume valuable odds.
Which is preferable: decimal or fractional betting odds?
There is no monetary difference between the value of fractional odds or decimal odds; they are simply different ways of displaying the same thing. Preference for betting odds comes down to personal opinion and what you find easiest to interpret.
Why has the usage of decimal odds become more prevalent in recent times?
Decimal odds are one of the most popular across the world, because many betters find them easy to understand. They are relatively quick to convert and, as the unit stake is always included, their value is always greater than 1.
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