Sportsbooks use 3 methods for stating odds: Fractional, Decimal, and American

Implied probability is also an important stat for evaluating a bet. It is the probability implied by the odds that the sportsbook believes an event will occur. Generally, you want to place a bet if you believe the actual odds of an event occurring are greater than what the sportsbook believes.

Fractional

Fractional odds are primarily used in the UK and Ireland. They represent how much you will win (potential profit).

For example, if you bet $10 at an odds of 3/2 the potential profit is $15 ($10 * 3/2) and the total returned is $25 ($15 plus the $10 stake).

Decimal

Decimal represents how much money will be returned to you, including your stake (total returned).

For example, if you bet $10 at an odds of 3.5 the total returned is $35 ($10 * 3.5), but the potential profit is $25 ($10 * 3.5 minus the $10 stake).

American

American odds are a whole different ball game. It is important to pay attention to the + or - sign in front of the odds. Positive odds represent underdogs and negative odds represent favorites.

Positive figures: The odds state how much you will win if you bet $100.

For example, if you bet $100 on an odd of +310, the potential profit would be $310 and the total returned would be $410 ($310 plus the $100 stake).

Negative figures: The odds state how much you have to bet to win $100 profit.

For example, if you see an odd of -220, you will have to bet $220 to win $100. The potential profit is $100 and the total returned is $320 ($100 winning plus $220 stake).

Implied Probability

Implied probability represents the expected probability a bet has to win. Each of the three odds can be converted into implied probability to help bettors evaluate betting value.