Definition
The average amount a bet is expected to win or lose per unit staked if it were placed many times, given the true probability of the outcome. A positive-EV (+EV) bet is profitable in the long run even if individual bets lose.
Related terms
- Edge — The model's estimated advantage over the market — the gap between its projected win probability and the probability implied by the price.
- Kelly Criterion — A staking formula that sizes each bet by its edge and odds to maximize long-run bankroll growth. Many use a fraction (half-Kelly) to cut variance.