
Have you ever been sitting there, waiting for your opponent to make a reasonable sized bet so you could call, then been taken aback when he made an obnoxiously large one? Maybe you folded because your pot odds were suddenly terrible. Or maybe you’ve been sitting on the river, waiting to check and fold, but your opponent made such a ridiculously small bet that you just had to call because the pot was offering 20-to-1. That’s because you’re a good player and you understand the fundamental poker concept of pot odds.
Good players usually have a fluid range of hands that they will call a bet with. They are generally willing to call a reasonable sized bet with a reasonable sized range, but when someone makes an unreasonable bet, they need a much stronger hand to call. For instance, betting $400 into a $65 dollar pot will not earn very many calls from a good player. It shows great strength and offers terrible pot odds.
This maxim does not hold true for most fish. Take the following example:

Against a typical player, betting $500 would be a huge risk, since they’re likely to fold even some very strong hands, like ace-ten, ace-jack, etc. But this is not a typical player. It’s a stubborn player with a wide range. Instead of having a fluid range of hands to call you with, based upon the size of your bet, this player has two types of hands – hands that will call and hands that will fold. Maybe there’s a third type of hand that will call a small bet like $50 – probably only pocket pairs – but all of those hands have 2 outs to beat you, and none of them will pay off a turn bet unless they spike a boat and stack you.
You may argue that by making a normal sized flop bet, a normal sized turn bet, and then a big river bet, you can string them along and take the whole stack on the river anyway. Maybe. But even stubborn, showdown bound fish will sometimes wise up when you make that river shove. You’re giving them three chances to get away from their hand.
With the over sized flop bet, you’re giving them one decision point in the hand. You’re asking, “Do you want to put all of your chips in with your three aces?” When you ask a fish that question, the answer is invariably yes. If there’s any way for them to talk themselves into a call, they’re going to call. And the bet of $500 was chosen just for that purpose.
What’s the first thought you have when someone makes a ridiculous sized bet? Why did they bet so much? It’s a natural question to ask yourself. By making the bet $500 and not $900 or $200, or even $510, you’ve given them an easy answer. Maybe it’s a typo!
Now the fish is thinking, “Yes, it’s a typo! I can’t fold three aces when this idiot’s large bet could have been a typo. He may as well have just dropped $450 dollars in there for me to scoop up. Thank you very much! … oh… you have a full house? Oh well. It could have been a typo, anyway.”
There are a lot of good players who have highly developed strategies for fending off the attacks of other good players. They have a decent sense of how to play against bad players, too. After all, it’s easy, right? Yes and no.
Sure, it’s easy to beat the fish. After all, they’re the reason we play. They’re not even trying to play well half the time. But here we’ve got another appearance of lazy edge syndrome. There’s a difference between beating the fish, and beating the fish for the maximum. Pounding the living daylights out of them. Here’s the thing about fish. If you don’t catch one yourself, someone else is likely to before you get another chance.
This practice of overbetting is just one example of a way to take maximum advantage of weaker players. It’s worth spending some of your thinking time pondering ways to do the same in other situations.
Here’s another example:

On the flop, you have an open-ended straight draw and make a no-brainer continuation bet. You bet again on the turn when you pick up a flush draw. The river is a total blank. Two flush draws and a slew of straight draws all missed. Nothing changed on this card.
Your opponent is loose and bad. If he flopped any kind of made hand – probably a pair of queens which just made trips – there’s little chance he’ll fold it to a river bet, almost regardless of the size. But you have seven high and there are a large number of missed draws in his range.
Sure, you could make a more reasonable looking bet. Maybe $250. But what hands are folding for $250 that won’t fold for $60? Those draws are going to check fold and think nothing of it even if you just sneeze on the pot. Your only goal here is to make the smallest bet possible that your opponent won’t just call out of sheer curiosity.
Now, a good player might not have that many hands that you beat on this river. He’ll check/raise the flop or turn with his draws. But the bad player is perfectly happy to call, call, fold with many of those. Is it a good line? Probably not. But that’s what makes him bad.
There’s nothing more frustrating than checking back with a seven-high busted straight draw and losing to an eight-high busted straight draw. So go ahead and sneeze on the pot. There’s no need to bother spitting. Your opponent won’t want to catch a cold.