Sniffing out flush draws

SUMMARY

You raise preflop and get a caller. The board is 2-suited, and the caller bets into you out of position. You raise small, he calls. He checks a non-flush turn, you check behind. The river doesn't help a flush, and he checks again (or bets tiny). You bet or raise damn near any amount, he folds. It doesn't matter what your cards are, but it's nice if you have cards (like two overs) that you would like to see a few more cards with before folding.


MORE IN-DEPTH DISCUSSION

You are CO and you have been dealt A:d: Q:c:. You raise an unopened pot to 3x, the small blind calls and the board comes J:d: 6:d: 2:s:. The small blind bets into you, 2.5x into a 7x pot. You have a few decisions:

1) You can fold and look for a better spot.
2) You can call and re-evaluate or make a play on the turn.
3) You can make a play.

(1) is certainly not a bad play. If someone is going to be betting into the preflop raiser out of position, we are quite happy to see that. So we missed our flop this time... no big deal. The problem is that we may easily be folding a better hand in a decent-sized pot to a tiny bet. I don't always like to drop two overcards so easily to what could easily be a bluff or a draw.

(2) has some merit... not the "re-evaluate" point, but the "make a play on the turn" point. If we have a read that an opponent will bet a draw on the flop and check it on a turn, this is a fine option. But this option doesn't give us much information. The opponent could easily be betting a pair of Jacks here, we have no idea. When an undercard comes, they are likely to fire again. If a K comes, they are likely to enter check/call mode. So I don't much like (2).

(3) is my favorite because it's so easy and it almost always works. All you have to do is raise to somewhere between 2x and 2.5x over their bet. If they reraise, we have to fold. However, a flush draw ALMOST ALWAYS calls, after all they're getting odds to see the next street at this point. The turn comes, there are a few scenarios:

a) The card does not help a flush draw, and it doesn't help us. Opponent checks (if they bet any reasonable amount, we're gone, but minbets are still usually draws). This is very frequently a flush draw, from what I've seen. I check behind, and the opponent thinks, "This idiot is letting me draw to my flush." When the river comes and it's not a diamond and our opponent checks again, they have given up. We can put damn near any bet into the pot and they will fold. I like a nice 1/4-1/3 pot "value bet" here, but I've even seen folds to a ridiculously small bet. How often have you been taking an opponent to value town and you put in like 2BB on the river and they fold? You will often get called by crappy pairs (if they have one), but at least you got a chance to see two more cards to help your hand, and also a great shot at taking down your pot (as opposed to giving up on the flop).

b) The card does not help a flush draw, but it's an A or a Q. In this case, our hand is usually good. We should be betting this turn to get value from a drawing hand or an underpair (at least 1/2 pot).

c) The card completes the flush draw, and the opponent bets into us. If they bet 1/2 pot or more, I'm gone. We can pretty safely say they hit their flush. If they bet less than that, I like a flat call in this particular instance, because we still have the nut flush draw, and if we hit our diamond on the river, we should be able to get a lot of value out of our nut flush, if not their whole stack.

d) The card completes the flush draw, and the opponent checks. This is slightly tougher, because now we have to wonder if maybe they weren't just bluffing or on some strange open-ender or gutshot draw. It's especially tough if it pairs the board. Maybe they hit trips? At any rate, I don't bet into this pot. Most of the time it's an opponent who is slowplaying their flush, and I just check behind with a chance to hit the nut flush. Now, if the river comes and they check again, I do as in (a), putting in a small bet, and drawing hands go away. If we hit our A or Q on the river, I simply like a check... no use getting blown out of a hand we might be winning.

The trick is, people ALMOST ALWAYS bet flush draws, especially in multiway pots. It must be something that they've seen on TV, and they figure it's a good play (of course, it often can be). People sometimes bet open-ended straight draws, and they almost never bet gutshots (but bad players will happily call down with a gutshot, and call a river value bet after hitting bottom pair). How often have you cbet or raised with a flush draw, gotten a call and a check on the turn, and you were just happy to be able to see a free river, thinking, "What an idiot to let me draw like this."? Of course, once you miss your draw, you're in check/fold mode. Bad players will do this same exact thing, and they won't even try to guess what you might have.

I'm not advocating this as something to do all the time, but as a strategy to use when you have a hand that you aren't quite ready to lay down yet. I'm not sure how +EV it is, and it's certainly not something to try against aggressive postflop players, but I've been able to do this with total air (even with rags from the BB in limped pots) and take down the pot pretty easily without very much risk.

I'd be happy to see a more experienced player comment on this idea.

Sorry but this is way too much text to read. be more concise.

Sorry, I was trying to explain my reasoning and a lot of the possible scenarios in my initial post. I thought that might be helpful to some people. I edited it to add a brief summary of the concept.

so you're trying to hammer out a line where you exploit a flush draw, so why don't you bet the turn? They'll still fold the river if the miss and it's like free money!

^What he said really^ If you think they are on a flush draw but will fold to any river bet when they miss, bet the damn turn with your entire range (including air).

I do this sometimes, but a lot of these players will call if they hit any middle pair on the turn or river. By checking the turn, we keep the pot small, and we're throwing away less chips on a river bluff that gets called. Plus our opponent isn't always on a flush draw after the flop action. Sometimes they are on a weak top pair or middle pair, and they're not folding unless we make a really big bet. It's close, though. Against a better opponent, someone who can lay down weak pairs, betting the turn is fine. Against a lot of the loose/passive types that I run into at low stakes, you might as well be throwing chips into the wind on the turn and river if they've happened to catch any part of the board.