Quote Originally Posted by CrunchyNuts
He had to pay 19BB into an ~35BB pot, with the lowest stack (hero's) remaining at about 110BB. He, if thinking, knows he only wins if he hits the flush, so he's got 9 outs (only 8 are clean, but he doesn't know that), giving about a 20% chance of taking the hand. He's paying 19BB, so with 20% to win, he needs to be winning 5x that, or about 100BB. Pot is only 35BB, so implied needs to be worth 65BB coming out of you. You have 110BB behind, so if he can stack you it's good - but flushes are pretty easy to see, it's unlikely that a stacking is going to happen here.

As it turns out, he hit and only extracted 40BB from you. If that was the plan, then the turn was -EV for him.
Villian gets the 36BB in the pot and another 40BB from me by calling the 19BB bet. So in his bet on the end he has actually undercharged himself slightly for the draw becuase he loses 19BB * 4 for 76 and only gets 75BB once since one of the BBs went to the rake. If he wouldn't have given me 2.3-1 on the end he most likely wouldn't have even gotten that. Which brings up another excercise I am working on. EV expressions for these situations.

As of the turn is it really worth trying to figure out just how -EV the call is since there are a multitude of factors or is simpler to just take the most likely draw and work from there as in this example. I'd like to sit down and pen out an equation but the exactness of it would probably far off. It's probably easier to say 4/5 he misses the flush and if you only pay out this much you didn't justify the call when he does, .10 they'll hit the 9 or K and lose their stack, .15 they might bluff off this much on the end etc. without getting a precise EV.