Bet sizing and fold equity go hand-in-hand, but their relationship is often misunderstood. In fact, it’s easy to misunderstand bet sizing as it has a commonly accepted (but incorrect) premise that is incredibly logical: larger bets create worse pot-odds for your opponents, therefore larger bets create more fold equity; and, in the reverse, smaller bets create good pot-odds for your opponents, so they create less fold equity. It makes a lot of sense, but it’s unfortunately not always right. And, when it comes to creative bet sizes (like over-betting or under-betting the pot) it’s dangerously wrong.
So what is right then? Bet sizing affects fold equity in a very specific way: large bets make your opponent more likely to do whatever it was they wanted to do and small bets make your opponent more likely to change his mind. This doesn’t mean that if your opponent was planning on calling the river and you make it small he’ll definitely fold, or vice versa. However, it’s a more accurate way to think about bet sizing than the classic “if I bet more he folds more” model.
I’ll provide some examples in either direction. Anyone who has ever experimented with over- betting has seen a situation like this: you raise Q♠T♠ on the button and get called by a regular in the big blind. The flop comes down A♠K♠8♣. He checks, you bet, and he calls. The turn is a 6♦, he checks, you bet again, and he calls. The river is an 8♥, and he checks. You decide to over-bet the pot—it’s an ideal spot as he’s calling for a chop with an Ace, while you have plenty of value combos that beat a chop (AK, KK, any 8). But, despite your well-crafted plan, he still calls with AJ. The reason is simple—he was bluff-catching the river, and your large bet inclined him to continue bluff-catching. In this case you probably couldn’t have made him fold for any amount, but you could have chosen a more effective size for your bluff. Then, the tricky part is to remember that you need to overbet for value in those spots against that player!
In contrast, let’s say that you call a raise in position with KQo. The flop is AT4 and your opponent c-bets. You call and the the turn is a 3o. He checks, and you decide to wait to bluff until the river so you check back. The river is a 7 and he checks again. You decide to bluff, and you’re almost positive your opponent folds every time. Even if he has a hand like JT, he’s still thinking about folding.
However, if you bet half-pot, he’s likely to change his mind and call. If you over-bet, however, your opponent will be compelled to do whatever he was leaning toward doing in the first place—in this example, folding. If I had a hand like 53s instead of KQo there, I would almost certainly show my hand after he folded. This creates a good relationship that will likely cause him to play badly in future situations (this is further discussed in the chapter Creativity, Bet Sizes, and Pseudo-Thin Value).
Let’s look at some value-betting examples now. I was playing heads up in a tournament and I raised K3o on the button. My opponent called. The flop was 973. He checked and I bet (a two-way bet—this will be explained in the chapter “Advanced Street Projection and Two-Way Bets”). He called.
The turn was a 2 and he checked. I decided that I could neither bluff nor get value, so I checked back. The river was a K, and he checked again. In this instance, I think he’s likely to lean toward calling a bet. He was a regular, so I knew that the scare card was likely to reduce my fold equity. So, I bet two-times
the pot and he called instantly with KT. I think he would have called with any pair and quite possibly ace high. However, if I had bet half-pot, I might have induced folds from those hands (by representing a thin- value bet).
We raise TT and our opponent calls on the button. We have a read on him—he likes to make big folds. The flop is T94, so we bet for value and he calls. The turn card is a 3, so we bet again and he calls again. The river is another 3. When we value-bet here, we’re hoping to be called by a 9 or a low pocket- pair. Against some people, we might want to over-bet for value here, but against this opponent, we want him to change his mind. That means betting small (see the section on Pseudo-Thin Value).
If you’re having a hard time judging whether or not you should bet large or small, I’d recommend practicing the Either/Or Philosophy. We’ll talk about that now.