Okay so I can’t get the hand history to work from Microgaming so will attempt to just write it out. Been thinking a lot about this hand and think I made a big mistake folding river.

Three handed. Effective stack 200bb. I open pot on the button with KKJ5ds. The sb folds and the big blind pots. I call. I think this is fairly standard. No history with villain. I do have him tagged yellow which means that he kind of knows what he is doing but is on the looser side.

Flop is 472 all diamonds giving me the second nut flush. Villain check calls 75% psb.

Villain checks a Ten on the turn. This is where I think I make a big mistake, I check back. My reasoning being that if he has AAxx no flush , I’m miles ahead, like have him pretty much drawing dead and am crushed if he has AAxxdd

River is a Q. Villain checks again so I go for value and bet 75% pot and villain rips it in my face, check raising pot.

Now, Is villain ever playing the nut flush like this? I mean ever. I have the second nuts and there are 4 diamonds on the board and two in my hand.

I remember listening to a Phil Galfond video where he says when things don’t make sense a good default strategy is to just call. I folded. I levelled myself into a fold where I think it should have been a clear call, as am at the near top of my range..

I think my turn check back made villain think he could successfully turn the nut flush blocker into a bluff, as most people would be going for 3 streets of value with the second nuts here.

Thoughts?