[admiralfluff]

From a theoretical standpoint:

Equity is an actual measure of a portion of the pot. Pot equity is comprised of our hand equity + our fold equity. Our hand equity is the % that our hand will win at SD, times the value of the pot. Our fold equity is the equity gained by a fold of our opponent times the chance that he folds.

An example:

We are at SD with A8o HU OoP on a KQ526 rainbow board.

In order to make a bet profitable based on pot equity, we would want our opponent to have a worse hand more than 50% of the time when he called. If we knew our opponent would fold 70% of the time, we would require him to have a worse hand and call 15% of the time to make a bet profitable. Because there are 2 opponents on the river, 50% of the river bets is even equity. If we get 2 bets in on the river (1 from us, 1 from villain) and win more than 54% of the time. our equity edge is 4%*(bets in on river). Hence we get a positive return on our investment.

70% is not our folding equity. When villain folds a worse hand on the river, we gain no share of the pot. We only care when villain folds a better hand. Unlike our SD pot equity, our folding equity is a return percentage on the entire pot, not just the river round. If villain folds a better hand 1% of the time, our folding equity is 1%*(whole pot). So the complete requirements to make a profitable river bet, (are SD equity edge) * (bets in on river) + (fold equity) * (whole pot) > 0.

So betting and folding a better A sometimes can add signidicant value to a bet, which could make a bet correct even if he has a better hand far more than 50% of the time when he calls.

Considering soley how often our opponent folds is meaningless from an equity standpoint. We must consider how this fold changes our long term share of the pot (our EV)

So back to the OP, if our opponent will never make an incorrect fold on the turn we have no fold equity, and how often our opponent folds to our turn bet should not be a consideration. Howver, when our opponent calls our turn bet knowing how often he folds is important, but for different reasons. Once he calls, how often he folds will reshape the probability distribution of all of his possible holdings, effecting future decisions, but not the decision to bet the turn.

Of course, there are other ways to evaluate any problem, but the above method is probably most copasetic for the human mind.