I am just reading about bluff catcher and want to know if I got this right?

So, bluff catcher is basically a hand you hold, that you cannot value bet with because it is not a very strong and it is a hand that cannot beat your opponents range of hands that he would value bet with.


Say I have A7 and I am up against a opponent that really likes to buff, pre flop my opponent just completes the small blind and I check from the big blind, the flop comes 369 rainbow, my opponent check to me and I bet, he calls, the turn comes 2, we both check and river comes 9, my opponent bets a small amount, I know he does not have anything because if he did have anything he would have would have raised on flop and bet on the river, after gathering information on him, I come to the conclusion that he is bluffing, so I raise.

Did I do this right?

So, a bluff catcher is a hand you call with because you think that the player has a lot of air in his range. Most good players will balance their action so that value bets for strong hands and bluffs look very similar. They will typically play medium strength hands differently. A bluff catcher is a hand that cannot beat any made hands.

In the example you put above, if you reraise, you aren't bluff catching, you are bluffing him or betting for thin value (depending on the bet sizing). He will not usually call you with a worse hand. If you called him, you would be bluff catching. Also, I am not sure I read his action as a bluff. I see a medium ace or a low pair.

Bluff catching is usually much more of an art when you do it against multiple streets of action.

I'd check the flop because I don't think I have enough equity to value bet even if the small blind calls the flop 100% of the time. Of course, the small blind probably won't call the flop 100% of the time, so there is some protection value to be had with a bet. However, just because he checked doesn't mean that you have the best hand on the flop. The small blind will have small pairs and decent draws at a frequency >0% of the time, which will cut into the profitability of a bet.* On the other hand, checking it back allows us to get one step closer to showdown, which is what Ace high unimproved really wants in this spot, and it allows us to improve for free when we're behind. That's like free money that you chose not to collect by betting the flop.

*I suggest you use equilab to see just how much equity a hand like 87o has against your Ace high on the flop. Then you should check out your equity vs your opponent's entire range of hands that the small blind could possibly hold. You might be surprised.

----

As played on the flop, I like the turn check for the same reasons I like a flop check. Then on the river, I think it matters just how much he bet as well as just how much you bet on the flop because the numbers will affect the ranges in question as well as the risk/reward ratio that will ultimately determine the profitability of bluffcatching on the river.

Here's the math:

If there's 10 bucks in the pot and he bets $5 on the river, then you're receiving 3:1 odds on a river call. This means that you need to win the pot with the best hand at least 25% of the time for a call to be profitable.

bet/(pot+bet) = the % of the time you must win to profit

5/(15+5) = 25%

You're investing 25% of the pot, so you must win 25% of the time for your bluffcatcher to be profitable. You might think that your opponent bluffs a lot, but even if he bluffs 24% of the time, then you're going to be losing money when you call. This is why it's so important to actually put your opponent on a range and then do the math. Combo counting is the grunt work of poker study, but it's quite fruitful if you do it right.

In laymans terms it means a hand that only beats a bluff and loses to your opp. entire value range on whatever street (in that your opp. isn't value betting worse which you beat).
Typically given certain actions taken by your opp., the absolute strength of your hand doesn't matter but the relative strength of your hand is described as a bluff catcher relative to your opp. range.

No you don't value bet w/a bluff catcher unless your opp. will call w/worse or you beat a portion of his value range, but you can turn bluff catchers into bluffs in some spots.

Forgive me for saying so, but this made me laugh a lot.

If you have a bluff-catcher, you use it to catch villain's bluffs. By CALLING.

FWIW, I would often fold that river. Villain usually has you beat, probably with a 6 or a random pocket pair. (Although he should generally be check-calling with hands like those, as they would be decent bluff-catchers themselves). If you raise, it's because you're bluffing in order to try and make villain fold a better hand, and the reason you're raising is because you don't think your hand is strong enough to catch bluffs.