Villain is 26/20/6.3 600 hands
I didnt have any notes on him and dont remember playing with him much tbh. I dont know why I think his line is
FOS it just doesnt make sense to c/r on that board wit a decent hand.
I think I can also raise here but didnt want to fold out his bluffs or Tx hands.

Should I be folding flop? Turn? River?

IPoker, $0.10/$0.20 No Limit Hold'em Cash, 4 Players

BTN: $12.14 (60.7 bb)
SB: $34.86 (174.3 bb)
BB: $32.21 (161 bb)
Hero (CO): $26.38 (131.9 bb)

Preflop: Hero is CO with K K
Hero raises to $0.80, BTN folds, SB calls $0.70, BB calls $0.60

Flop: ($2.40) T 8 4 (3 players)
SB checks, BB checks, Hero bets $1.60, SB raises to $5, BB folds, Hero calls $3.40

Turn: ($12.40) 6 (2 players)
SB bets $7.40, Hero calls $7.40

River: ($27.20) 9 (2 players)
SB bets $21.66 and is all-in, Hero ?

If he is going to bluff he will do it with equity like oe, gs and gutshot draws got there. so he has sets,str8's or maybe 108s. i fold otr for sure until i have a good reason to believe he is bluffing good% of time and we might even consider folding ott(not many cards that we will like seeing otr).

I actually do not think he has T8s or sets. Look at the board, would you still valuebet a set with this sizing here? So if Villain chooses this sizing, I am inclined to believe that he is polarized between a straight and complete air.

Next question is what he could raise the flop with. Assuming he thinks rationally which is indicated by his stats, he will have some sort of equity if he checkraises the flop. That could be backdoorflushdraws, overcards or gutshots/OESDs. I am not quite sure what villain is calling here in the SB so I won't try to give him an exact range, but out of the possible hands he could have raised otf and barreled ott only 97s, 76s and maybe 87s and 77 got there. Those are 15 combos (and one might argue for discounting 87s and 77 here since he may have just called them on the flop since he had showdownvalue with his pair). We need about 25% equity for a call here, so he would have to bluff 5 more combinations for a slightly +EV call. Given that he has an AF of 6.3 and KK is near the top of our range I think we should call the river.

^^ size ott is fine with a set, you don't want to chase away ovp's and j9s. No need to bet more ott for value really, cause it will be less than psb otr anyways + it's good for the times you actually bluff. You've got a point for him being aggro but you think the 9 otr is a good card to bluffcatch him?

Noticed my mistake. I was referring to him pushing the river but overlooked hero not being as deep as him. This actually makes sets more likely, although I'm still not convinced that he will bet all of his sets on this river 100% of the time.

My main point was that this river is a bad card for continuing valuebets he made on flop and turn since there are four cards to a straight out there that are very likely to scare your opponent into folding worse hands. Obviously this makes it a very nice river for a bluff and I think a Villain as aggressive as this will surely notice this and bluff with a relatively high frequency here. So I'm not saying that this is a great spot to bluffcatch in, but that against this specific villain it might be a decent one, especially since we are unlikely to ever have a hand we can actually call here (read: a straight).

YEah, I just though that the 9 OTR would be more likely to make him ck anything he reps OTF/OTT so it looked like a really bluffy line to me.

Now that i think about it more, it might be a decent spot to bluffcatch. I think this is either fold turn or if we are going to call this turn we need a plan otr before calling, like on what cards we will try to bluffcatch him when he shoves.