What is Implied Probability?
The probability of a result that a sportsbook's odds are pricing in — calculated as one divided by the decimal odds.
Implied probability translates a sportsbook line into a percentage. It is what the book thinks (or what the book wants you to think) the chance of the bet hitting is. When your own assessment of the win rate is higher than the implied probability, the bet has positive expected value.
Example
Decimal odds of 2.50 imply a 40% chance. American odds of −150 convert to decimal 1.667, which implies a 60% chance.
Related terms
Expected value (EV) is the average profit or loss a bet pays per dollar staked if you repeated it under the same odds and probability forever.
The sportsbook's built-in margin — the gap between the sum of implied probabilities across all outcomes and 100%.
Betting only when your estimated win probability is higher than the bookmaker's implied probability.
See implied probability applied to a real slate
NotaSportsGuru runs the math behind every published leg — Parlay of the Day, player props, match lines — with the model’s expected value and edge on every line.