Read on villain is that he's a terrible player. This is the first hand, but we've been playing enough for the last few days to pick up a read on him that he's a fishy player.

$50 DoN, Merge
Blinds 10/20

SB: 1500
BB: 1500
UTG: 1500
UTG+1: 1500
UTG+2 (Villain): 1500
UTG+3: 1500
MP1: 1500
MP2: 1500
MP3: 1500
CO: 1500
BTN (HERO): 1500

Dealt to hero KK
2 folds, UTG+2 calls 20, 4 folds, Hero raises to 80, 2 folds, UTG+2 calls

Flop: Pot 190
936

UTG+2 checks, Hero checks

Turn: Pot 190
9

UTG+2 bets 100, hero calls

River: Pot 390
A

UTG+2 bets 350, hero folds

I suppose I'll withhold my reasoning on my line until I get some opinions.

I think I would take the exact same line.

same ^

if he checks to you ott, what is your action?

Sometimes I will bet out but usually just check it back and get one street of value on any non diamond/non ace river. I believe my strength to be bubble play so I just try to get there as cheap/low risk as possible. Although I do believe that is a great board to value bet, I will only do it occasionally as I think it turns our hand face up. I seldom, if ever, bet this board on a bluff.

On that card I think I have to check back. I would probably get more value betting the flop than on that turn. There's a lot of other turns that I could go for value on though.

I would bet flop around 75 for value.

Well I actually know what villain had since he decided to show after the hand (lol).

Anyways here's what I was thinking throughout the hand.

Pre obvious iso raise

Flop I thought his range pre was something like all pairs, suited connecters, medium strength offsuit aces, broadway connecters, and suited aces. Using that range I figured this was a pretty clear way ahead/way behind spot where I could really only get value from ATo+ and KQo when he had like the Ad or Kd. It didn't really make sense to go for value considering that if he didn't have a diamond draw I was going to have to get value from a hand that had 2 or 3 outs. I also thought he would bet the majority of his diamond draws on the turn if I check back and the turn bricks so that I would get value anyways. The majority of his range is just folding to a bet and drawing really thin against me or it's crushing me with flopped flushes/sets. If I get c/r here I'm in a terrible spot because he would want to do that with hands like 77, 88, TT-QQ as well as sets, fearing the diamond draw.

Turn, the 9 is essentially a brick so I expect him to be betting it a lot and my range is very Ax heavy so he's probably going to be bluffing it a lot. I don't really think I can narrow his range at all given his sizing and previous action. I think I have to call this because his range is full of crap that I'm absolutely crushing.

River, I kind of like the river ace. I really doubt he has an ace here, mostly based on his sizing. If he had an ace he wouldn't want to bet so big because I have AK/AQ here a ton. I don't think he's ever got AK and I also think it's pretty unlikely he's got AJ/AQ because he limped pre. Maybe he can have like ATo, but that's a strange sizing for such a weak ace. Weak suited Ax hands are going to tend to bet smaller here as more of a combo blocker/value bet because an ace with no kicker here is pretty weak. This bet seems like it's either a bluff with air or a value bet against the Ad.

So what I'm left with is a polarized range of hands that flopped incredibly well and bluffs. Since I thought most of his bluffs on the turn were AX hands and now I am removing the AX hands from his range I'm left with a range that is mostly value hands against my AX with maybe a few busted K high diamond draws. I decided to fold and got shown 7d8d for the flopped flush with the straight flush draw.

I think you played the hand fine but the flop is very far from a way ahead/way behind situation on the flop.

I don't mind the flop check because getting c/r on the flop sucks like you said.

I mean maybe if he's got a lot of off suit aces in his range, but idk if he goes below ATo pre. How low do you think he goes with off suit aces?

100 pre if he's terrible

bet the flop ???

as played on flop turn/river are fine

Why can't he have JdTx and about a zillion other 1 diamond hands if he's fishy?