Fold equity
Fold equity is the value a bet or raise gains from the chance your opponent folds, letting you win the pot immediately without needing the best hand.
A bet wins in two ways: sometimes it gets called and wins at showdown, and sometimes the opponent folds and you take the pot uncontested. Fold equity is the value that second way adds. It is why betting so often beats checking, even with a mediocre hand, and why a draw can be worth raising before it has even completed.
For a pure bluff, the fold frequency needed to break even depends only on the bet size relative to the pot:
fold% needed = bet / (bet + pot)
Worked example. The pot is 60 and you bluff 40:
fold% needed = 40 / (40 + 60) = 0.4
Your bluff needs a fold four times in ten to break even. If your opponent folds more often than that, betting shows a profit even though your hand has no showdown value on its own.
Fold equity is highest against opponents who can comfortably let a hand go, and against ranges that have shown weakness already. It is lowest against players who call almost everything. Read the opponent before you fire, not just the cards in front of you.
Put it to work with the MDF calculator.