Implied Probability Explained

Implied probability converts betting odds into the percentage chance represented by the price.

Decimal odds

Implied probability equals one divided by decimal odds. Decimal 2.50 implies 40%.

Positive American odds

For +150, implied probability is 100 divided by 150 plus 100, which equals 40%.

Negative American odds

For -200, implied probability is 200 divided by 200 plus 100, which equals 66.67%.

Bookmaker margin

The implied probabilities in a market often add to more than 100% because of overround.

Fair probability

Compare the sportsbook's implied probability with your own estimate.

Professional approach

Use implied probability as the bridge between odds, expected value and model forecasts.