How to detect when your opponent flopped a set?

Question

This is one area where I lose the most amount of money in poker because board texture doesn't give too many clues as long as the opponent's bets are sized correctly. Here's one example I faced today:

It was a 1/3 cash game. I had K4s on the button. One player raised to $15 and one called. A $15 raise was typically the minimum at this loose table. I decided to 3-bet to $45 as a semi bluff. One player called (not the initial raiser). The flop came K83 rainbow. All I had was top pair with a weak kicker. My opponent bets $30 out of turn. I thought that was suspiciously small so I decided to continue the story that I had a strong hand: I raised to $90. He called. The turn was a queen. He checked, I checked. River was a 7. Now he bet $150 out of turn. I stupidly called and he showed pocket 8s to make a set.

I know I violated the rule that I should fold to a big river bet if I can't beat the hand he's representing. But the way I justified making the call was he was asking for $150 to win a $450 pot so my bluff catch had to be right 33% of the time. And I caught him bluffing tons before.

My question is how could I have avoided the river call?

He made his river bet 1/2 pot so it didn't set off any alarms to me. I suppose the clues were that he called my 3-bet both times and then tried to trap me with a check on the turn.

Answer 1

On dry boards like your flop, it's generally hard to raise and 3-bet in a balanced way. It's possible, but it's hard to find natural bluffs. I like to just to bet small with a wide range as the aggressor, and call/float wide as the defender on these dry boards.

In this particular hand, I'd say a couple more things. Pre-flop he cold called a three-bet out of position, and then lead into you on the flop (donk betting). These are things that strong players generally don't do (I mean maybe it's possible to build a balanced donk-betting range, but it's much simpler to just check with everything). From these two actions I would assume that he's not very strong, unless I had reason to think otherwise. I'd note that he's donk-better whose checking range is probably very weak, and try to steal a lot of pots when he checks to you.

When someone does cold call a 3-bet in a (potentially) multiway pot out of position, it's often a low-to-mid pocket pair looking to set mine. When he donk-bets on the flop, I think you should just call. This is another disadvantage of donk-betting, it lets the opponent (i.e. you) play their range easily and naturally. Your raise on the flop illustrates the point in my first paragraph: I guess you're representing pocket kings, or maybe AA/AK - but what hands would you use to bluff here? I also doubt that raising pocket kings is very good here either. There's little chance of being outdrawn on such dry boards, and you can look to put pressure on his range on later streets. Assuming both your stacks are around 100 big blinds, you can still get him all in by the river with KK etc., with mostly anything he'd call you with on the flop, so don't worry too much about raising the flop. I'd let his range catch up a bit. With your particular hand, I'd call the flop, and fold turn or river to further aggression.

EDIT: I just realized I misread something about the OP. I thought the villain cold called a 3-bet from the blinds, but I just realized that he was the first initial caller. I'd still say he's quite likely to have a low-to-middle pocket pair in his range anyways (calling a raise, then calling again after a 3-bet) so I think much of the analysis still stands.