The difference between fractional/decimal/American odds

If you are having your own sports bet of the year this weekend on the SuperBowl the way different bookmakers compile their odds might confuse you.

The SuperBowl takes place this weekend and for a lot of poker players it is the only time they bet on sports. However, despite understanding odds in poker, the way sports betting markets are presented can be confusing.

Whether you like to bet on markets or not it is a useful thing to be aware of as a poker player. What you are looking at there is the difference between fractional odds, decimal odds, American odds and implied probability. 

Fractional Odds

The most commonly used odds format, especially in the UK and Ireland. They are displayed in the format of two numbers with a slash between them, ie. 2/1. 

The first number is the amount you can win, the second number is the amount you have to stake. So if a bet is 2/1 you would have to bet $1 to win $2. The amount of money you would get back would be $3 (your $2 profit and $1 stake).  

At the time of writing Kansas City Chiefs are 1/2 to win and the San Francisco 49ers are 13/8 to win. If you bet $10 on Kansas you would get $15 back ($10 stake + $5 profit), if you bet $10 on San Franciso you would get $26.25 ($10 stake + $16.25 profit). The lower return for the Chiefs means they are the favourite to win. 

Notice that the 49ers are not automatically 2/1 to win even though the Chiefs are 1/2, the small difference is essentially how the bookmakers make a profit regardless of the outcome, by charging a small premium on the odds, as well as the chance of a draw. 

Decimal Odds

Decimal odds are common in Europe and Australia, but have become more mainstream in recent years especially since Betfair was launched. They are arguably easier to understand than fractional odds. 

A decimal odd shows you the amount you would win, including your stake, if you bet one unit ($1/€1/£1). They are always shown as a number above 1 with a decimal point, like 2.0. 

In the same example as before, the Chiefs at 1/2 is 1.5 in decimal odds (A $10 bet would return $15 total) and the 49ers at 13/8 would be shown as 2.63 (a $10 bet would return $26.3 - note that it rounded up compared to the previous example, decimal odds are shown to two decimal points).

American Odds

This is where some may get confused, because we don't see Americans talking so much about sports betting odds so the way they show their working out can be confusing to some. 

American odds, or 'Moneyline' odds are shown as a plus or a minus amount, ie. -200 or +200, The moneyline indicates the amount you would need to wager to win $100, then depending on whether your pick is the favourite shows a plus for the underdog or minus amount for the favourite. 

One more time, on the moneyline for the above example, the Chiefs are -200 and the 49ers are +163. That means to win $100 profit on the Chiefs you would have to wager $200, but if you bet $100 on the 49ers you would make $163 profit. 

Implied Probability

You probably won't see people making wagers with percentages but they are useful to provide context for the other three types of betting format. 

You can convert betting odds into an implied percentage chance of happening, which is very important for you to cross-reference with your own assessment of the thing you are betting on. 

The 1/2 odds for the Chiefs implied they are 66.7% likely to win the match the 13/8 odds for the 49ers when we wrote this implied a probability of 38.1%. If you think the Chiefs were 66.7% likely or better to win the match, then the 1/2 odds are a good bet. If you think the 49ers were only 20% to win the match, then the 13/8 odds are not worth it and you would want closer to 4/1.

We have compiled how to convert the different types of odds to the others and you can play around with all of them using the calculator below:

Free prizes for making your Super Bowl predictions

On Sunday the eyes of the world will turn to Las Vegas where the Kansas City Chiefs take on the San Francisco 49ers to once again find the best American Football team of the 23/24 season.

And just like last year, bet365 is once again running a straightforward prediction contest that could see you win up to €1,000 in cash if you are able to predict the outcome of the Big Game in regulation time.

In order to do that, you'll have to opt-in to the contest via the Mission section in the bet365  software, slot in your prediction the latest until this Sunday, February 11, 23:30 GMT, while also generating at least €10 in rake or tournament fees at bet365 to make your prediction count. You can either pick the Kansas City Chiefs, the San Francisco 49ers, or a Tie—as the prediction is based on the outcome of the game in regulation time, not including any possible overtime.

If you picked the right outcome, you will then be awarded one spin at bet365's so-called Winner's Wheel within 48 hours, giving you the chance to bag prizes ranging from €0.50 cash all the way up to €1,000. See the table below for a full breakdown of possible prizes and the likeliness of hitting them.

Touchdown and win up to €1,000 cash at bet365

Taking part in a nutshell

• Create a bet365 account via PokerStrategy.com if you don't have one yet.
• Opt in to the promo through the Missions section of the bet365 software.
• Predict the outcome of the game in regulation time and generate €10 in rake and/or tournament fees.
• Receive a spin on the Winner’s Wheel if your prediction is correct and a shot at up to €1,000 in cash.

That's it—just keep in mind that you must slot in your prediction and fulfill the rake requirement until this Sunday, 23:30 GMT. Below are all the prizes on offer if you manage to pick the right outcome. Good luck!