Sports Betting Odds Explained

Sports Betting Odds Explained 

What are Odds?

Odds are a numerical expression used in gambling to reflect the ratio of payoff versus the stake. The odds are also generally reflective of the bookmakers view of the likelihood of an outcome happening. There are a few different types of expressions of odds. On our site, you can view the odds in either American format, or decimal format.

What are American Odds?

American Odds are expressed with either a plus (+) or a minus (-) sign in front of them. Teams that have odds with a minus sign are the favourite to win. The minus sign indicates the amount you need to bet on the outcome for you to profit $100.

Teams with odds with a + sign are the outsider to win. The number following the plus sign reflects the amount a bettor needs to place on the outcome to profit $100. Let’s work through a couple of examples. Let’s say we have the Golden State Warriors taking on the Chicago Bulls and a bookmaker has odds at the following quotes:

Golden State Warriors: –255

Chicago Bulls: +212

The Warriors are the clear favourites, therefore they have a minus (-) in front of their odds. Their odds show that you’d need to place $255 on them to win back $100. The Chicago Bulls, they’re the outsiders, and in turn have the plus (+) in front of their odds. Their odds show that if you place $100 on them, you’d get back $212 if they won.

In short, if you see the minus sign just think: I need to put $x amount on the outcome to win back $100.

If you see a plus sign then think: If I put $100 on this, then I’ll get back $x amount.

What are Decimal Odds?

Decimal odds reflect the amount you get back if you place $1 on the outcome, and it wins.

Therefore:

  • The less likelihood a sporting outcome is of happening, the higher the odds. In turn, the higher the payoff will be relative to the amount you’ve staked. The term Stake means the amount you risk or put forward for the bet.
  • The more likely a sporting outcome is of happening, the lower the odds, and in turn the payoff is lower relative to the stake.


Let us illustrate with an example. If a sporting outcome is at decimal odds of 10.00, a $1.00 bet would yield a return of $10 if the bet was successful. The total profit would be $9.00 as the return includes the original $1.00 that was staked. The probability that this outcome is of happening is reflective of approximately 1 in 9 probability. One thing to remember is that the bookmaker will include a margin within their odds that they quote. This can be anywhere between 5-20%. So if the bookmaker truly thought an outcome would have 1 in 9 probability of occurring, they would quote odds closer to 8.00 or 9.00.

Another example, if a sporting outcome had approximately around a 50% chance of happening, it’s odds would be closer to 2.00. Odds of 2.00 would mean that if a $1.00 was placed, the return would be $2 and the total profit would be $1.00.

What are Fractional Odds?

Fractional Odds are one of oldest expressions of odds, and are commonly used in Horse Racing. Fractional Odds are expressed much like the fractions you would’ve done back in school maths class. Here are two examples of how they are represented:

Example 1: 2/1

Example 2: 18/10

The number on the right of the forward slash (/) represents the denominator, and the number on the left represents the numerator. Therefore, in example 1 above, for every $1 you place on the outcome, you will receive $2 back if it wins. In example 2, for every $1 you place on the outcome, you will receive $1.80 back. In most instances the denominator will be expressed as a 1 (e.g. 3/1, 4,1, 20/1). However, when the likelihood is not a round number, the denominator will be shown with more than one number (e.g. 18/10, 35/10, 210/100).

If you have odds of 10/1, you can read the odds as the probability of the event in happening at about one in ten (excluding the sportsbook’s margin).

If you’d like to convert fractional odds into decimal odds, you simply need to add the two numbers together:

8/1 - 8+1 = $9.00

If the fractional odd is two digits, then the calculation is slightly different:

18/10 – (18+10) / 10 = $2.80

Other thing to note, the odds may also be represented in commas, where the forward slash (/) can also be represented in a colon (:). This doesn’t change the way the odds are to be read.