Fold Equity

The share of a bet's profitability that comes from opponent folds

Definition

Fold equity is the share of a bet's expected value that comes from the probability that your opponent folds. Every aggressive bet has two ways to win: immediately (the opponent folds) or at showdown (they call and you win the hand). Fold equity measures the first. It's the engine of the semi-bluff: betting or raising with a draw combines your fold equity with your hand equity. Even if the opponent calls, your draw keeps ~35% equity; if they fold even a third of the time, aggression becomes clearly more profitable than passive calling. It's also why shoving 15bb with A5s is profitable where flat-calling an open with the same hand is not. Fold equity depends on three factors: the opponent's range (the wider and weaker it is, the more it folds), the sizing (a bigger bet generates more folds, but risks more), and the perceived credibility of your line (a bet consistent with a strong hand gets more folds). It vanishes against an opponent who never folds — against a calling station, you value bet, you don't bluff.