Why would I turn a flush draw and not bet that turn? And when thinking through ranges, you can never ever say, someone will not do X in Y spot. Like as an example, I will never check two pair on the turn, which isn't true especially in this spot. It's especially true because he's a nit and I would have a better chance of extracting value on the river on a dry board then betting an ace. You want to build a case of likelihood, but I'd advise about getting too rigid in hand ranges. I somewhat fell victim to it here, and I'll say why later.
Hehe... ok, so clearly a lot of you would snap call with Kx. I'm finding it hard to believe based on experience, but....
He snap folded, but that's irrelevant.
Excellent points. You're right probably flush bets the turn. And you can't really say always or never. but maybe rarely or often are better terms.
So lets think about ranges and what a person would likely do with each given card.
Pre: CO raises - his range is marginally wide and getting in the stealing range. Pretty much all A's, a good number of K's, a few Q's, all PP's, and a reasonable number of suited connectors. We can call it 27%, maybe - depending on the player. BTN calls. BTN range should be maybe 10% of all hands. So pp's, a few A's, very few K's, mostly made up of middling connectors. Most everything else should be raising or folding. SB is a nit, I don't know what his 3bet range is, but we can likely remove AQ+, TT+, and maybe KQs. I don't expect to see him calling there is 78s, or similar middling holdings. So, probably mid PP's, A9-AJ, K9-KQ, QT+, JT, maybe T9. I think I stretching his range.
So flop is K 2 5. This is a flop that misses the CO solidly. It misses a lot of SB as well, and should miss the BTN. However it does hit a bigger portion of the SB's range - though he checks. As does CO. BTN bets, this doesn't really mean anything but will likely fold out most players. SB calls, so he either (likely) has a K or a PP.
Turn is an A. SB checks again. This looks like a pretty good scare card, gives a flush draw and it kills the K high hands. BTN checks. This check does a couple of things. either the BTN has an A, and is checking to get value on the river or he is checking because he doesn't have an A. Begs the question would a good player bet the A if he has it. Maybe not. I was about to get meta and say something like - the SB is a nit so the BTN is more likely to bet an A for value since the nit is more likely to call, but the nit is not likely aware of that.
River is a 6. It completes no draws and should improve very few hands. SB bets. If BTN has a PP or an A he is not likely to raise this. BTN should get very few calls from worse hands with a raise in that position. So this means that either BTN is
bluffing or has such a strong hand that he has to raise for value. What very strong hands would BTN have here that would either 1) not have been worthing trying to get a call on the turn with or 2)got there on the river. There are exactly 3 hands that fit this category. 56, 66, A6. All are in the realm of likelihood, however there is also a ton of air in there too. I really want to discount A6 here, because it seems like it should be able to get a bet on the turn, given SB's play. It also seems that SB may not give BTN credit for A6, given that there was no turn bet. This limits the big but likely hands to 56 and 66. So what does SB likely have? K9-KJ rates high up in the realm of possibility, as are pairs 77-TT - but those don't likely bet here. So K is the hand that bets here most of the time.
I think the reason this works is because the nit fears the A. The reality is that with a raise here, the K may as well be an A. an A should very rarely do this, since the only hands that call very often are better. Actually almost all pairs run at even
equity to an A based on that bet. Given how polarizing that raise is, its not necessarily a mistake to call this raise by the SB.
On the other hand, this only needs to work around 50% of the time to be profitable. And this line probably works close to that against a lot of players. I think most people fold here.
I wouldn't.