If you’re new to sports betting, the first thing you need to is understand the odds. BET.CA is here to explain how sports betting odds work, how to understand and compare them, and how to familiarise yourself with the different odds formats used by online sportsbooks.
Understanding the different types of sports betting odds and how they work will also enable you to compare odds between sportsbooks, meaning you'll be in a better position to identify where the value lies.
Odds represent a sportsbook’s assessment of the chances of an outcome taking place.
The odds are determined by skilled and experienced experts, who set the odds to ensure sportsbooks both encourage betting action on the event and have a strong margin for profit.
Sportsbooks have teams of experienced professionals, called oddsmakers (or traders) who set the odds for each betting market.
Oddsmakers are responsible for attracting betting action with competitive odds, as well as maintaining a strong profit margin for the sportsbook.
The sports betting market is growing in Canada, with two different groups of bettors preferring two different odds formats. Originally, sports betting was only offered via government-regulated lottery providers, with odds presented in decimal format, so longtime bettors in Canada will be used to the European decimal format.
However, the growth of sports betting in the US has led to the American "moneyline" odds format becoming very popular in Canada, particularly with fans who watch sports on television, with broadcasts of the major sports leagues often referencing odds using the American format.
Both formats, along with the English fractional odds format, are explained in detail below.
American “moneyline” odds are the most popular format in the US. They split selections into negative and positive odds, with negative odds prefixed with a minus symbol (-) to denote the favorite and positive odds prefixed with a plus symbol (+) to denote the underdog.
Negative odds show how much you have to stake to win $100, while positive odds show how much you stand to win if you bet $100. Here’s how a moneyline bet on an NHL game could look, using American odds:
A winning $100 bet on the Arizona Coyotes would return $420 (your $100 bet plus $320 in profit), while a winning $100 bet on the Calgary Flames would return $125 (your $100 bet plus $25 in profit).
Here’s how a Grey Cup futures market could look, using American odds:
For example, a winning $100 bet on the Calgary Stampeders to win the Grey Cup would return $650 (your $100 bet plus $550 in profit).
Originally used in horse racing betting rings, fractional odds are the most commonly used format by sportsbooks in the UK and Ireland. They are listed in a x/x format, with the second number indicating how many units you have to bet in order to win the first number in profit.
Fractional odds can be more difficult to compare to American and decimal odds, as the denominator part of the fraction (the number after the slash) can differ. For example, a winning bet at odds of 9/2 would reward $9 for every $2 bet. In effect, it means the odds are 4.5/1, but fractional odds never feature decimal figures.
Here’s how the match odds for an English Premier League (EPL) game could look, using fractional odds:
A winning $100 bet on Liverpool would return $112.50 (your $100 bet plus $12.50 in winnings), while a winning $100 bet on Watford would return $2,300 (your $100 bet plus $2,200 in winnings).
Here is how a World Cup futures market could look, using fractional odds:
A winning $100 bet on Spain to win the World Cup would return $900 (your $100 bet plus $800 in winnings).
Decimal odds are used most commonly by sportsbooks in Europe and Asia. They represent the total amount returned for a winning bet per $1 staked. Unlike American and fractional odds, decimal odds include the stake in the predicted return and are considered by many to be the easiest for new bettors to understand. To calculate your potential payout, simply multiply the odds by your stake amount.
Here’s how a moneyline bet on an NBA game could look, using decimal odds:
A winning $100 bet on the New York Knicks would return $275 (your $100 bet plus $175 profit), while a winning $100 bet on the Miami Heat would return $147 (your $100 bet plus $47 profit).
Here’s how an NBA Championship futures market could look, using decimal odds:
For example, a winning $100 bet on the Golden State Warriors to win the NBA Championship would return $675 (your $100 bet plus $575 profit).
Check our at-a-glance table showing examples of how the three odds formats compare.
Regardless of the odds format, sports betting odds reflect a sportsbook’s opinion of the probability of something happening. Being able to assess that will help you to make smart decisions when considering whether a bet is good value or not.
For example, a +200 bet (3.00 in decimal odds, 2/1 in fractional odds) is expected by the sportsbook to be successful once every three times, meaning its implied probability is 33.3%.
A bet at +400 odds (5.00 in decimal odds, 4/1 in fractional odds) is expected by the sportsbook to be successful once every five times, meaning its implied probability is 20%.
By understanding how sportsbooks view their implied probability of a bet winning, you can compare their view to your own. If you feel the probability of winning is higher than the implied figure represented by the odds, you can decide to back your judgement and place a bet.
While the true implied probability of any given betting market should add up to 100%, sportsbooks build additional margin into their odds to ensure a long-term profit.
They do this by tweaking the odds to raise the overall market’s implied probability to a figure above 100%. This is called the overround. The difference between the probability of an outcome and the odds offered is known as the vig, juice, or margin.
This is most easily seen in point spread markets, where markets are made up to be coin-flip bets. The true odds for a coin flip should be -100 (an implied probability of 50%), but a sportsbook would often set the line at -110 for each outcome.
To find out more, check out our dedicated guide to the vig.
All betting guides on BET.CA are written by in-our house team, who have over 40 years’ experience in the sports betting and gaming industries, and have worked and written for several of the world’s leading sportsbooks. They possess in-depth knowledge of betting markets and strategies, as well as an understanding of what is important to bettors, meaning you can read on with the confidence that they will help improve your betting.