Originally Posted by boomeranged
Let's say, you have a straight draw on the flop and there is 1000 in the pot. You are in position and the opponent bets 500 to you. So, with eight outs you have approx 32% chance to win it which gives you 1:3 ratio on winning the hand. At this moment if you call, you have to put 500 in the pot to win 2000 giving you 1:4 ratio on risk versus reward. Hence making it a profitable call as you have a better outcome if you win compared to how much you put in. You know what makes it even more profitable? Fold equity. What is Fold Equity? Let's say we have 50% chance of winning or losing any hand that we play against a single opponent and at the same time the opponent has 50% chance of winning it too. In the same scenario, you have 32% chance of winning the hand and assuming the opponent has the rest will be an intelligent assumption. Let's say when you reraise the already 1500 chip pot to another 1500 to play, you are giving your opponent the option to fold and hence 25% of his 50% share shift to your side of equation giving you 57% in total and hence improving your chances to win it. This extra leverage that you get when shifting your pressure on him and giving him the option to fold comes to your advantage in the long run and the money earned thus is called Fold equity.
Couple things to point out here.
First, I don't like describing 32% as a 1:3 ratio. This is confusing in poker terms. The actual card odds
ratio is 32%:68%, or basically 1:2. Which means you need at least 1:2 on your money to make a profitable call. This is your "card odds." If the pot is 1000, and your opponent bets 500, then you need to call 500 to see 1500. That's 1:3. That's your "pot odds". Mind you, that's 1:3 to hit your draw *by the river*...
Now as for "fold equity" that's a much dicier concept and very much an inexact science. "Fold equity" is what % of the time an opponent will fold to a bet, and you measure that against their perceived range.
For example let's say my opening range from UTG is AJ, AQ, AK, KQs, 99 to AA. If you 3-bet, hypothetically what parts of my range do I fold? AJ (16), KQs (4), 99, TT, (12) - 32 combos. What don't I fold? AQ (16), AK (16), JJ, QQ, KK, AA (24) - 56 combos.
So of 88 combinations, I fold 32. Your fold equity in this situation is 36%. In other words, 2/3rds of the time you're not getting a fold from a typical UTG raiser.
However, bearing in mind that you 3-bet preflop and depending on the board, you may have greater fold equity on the flop because of this.