Villain is 42/11/0.8 (25) over a small number of hands.Observation is that he has been very passive during those hands.

I want to check/fold turn even if it seems weak.
Convince me why I shouldn't.

Grabbed by Holdem Manager
Limit Holdem $10/20(BB) Replayer
SB ($342)
BB ($778)
UTG ($555)
UTG+1 ($265)
Hero ($285)
BTN ($1,898)

Dealt to Hero 6 6

fold, fold, Hero raises to $20, BTN calls $20, fold, BB calls $10

FLOP ($65) A K K

BB checks, Hero bets $10, BTN calls $10, BB folds

TURN ($85) A K K T

Hero ?

Sorry I can't. Feels like that turn nailed the guys coldcalling range. Sure he could have a heart draw of some kind like 98s or such but much more likely is a hand including an A, K, Q, J or T and likely in combination with each other. I guess alot of passives will call here with underpairs too. I would check and hope for him to be as passive as you describe and check the hand down when you beat him and bet when he beats you. And since I think you equity isn't good at all when he calls the flop I think we can live with not getting any more value when we are ahead.

I can't think of any reason why check fold isn't the play vs. this guy, unless you think he can fold a better hand.

The only alternative is to bluff and it is hard to make a case for that. You are in amazingly bad shape in terms of chance of finishing with the best hand.

Given your description there is a fine chance that if Villain has a flush draw he will give you a free card.

Fun facts about flush draws:

1. QJ and Tx represent a large part of his flush draw range after he coldcalls preflop.

2. Versus Q9 and many similar flush draws you have a 22-22 out split.

because you're so far behind, you think you're ahead?

I would c/f here as I don't expect him to fold a better hand and I doubt we have the best hand here.

The only argument for barreling the turn would have been to fold out QJ, QT, JT. That ship has sunk. 99/88 are 12 unlikely combos. In short, your hand sucks and his doesn't, so c/f.

I don't like the flopbet, 10$ into a 50+$ pot. Even QJ can call this along with flushdraws. But it does eliminate an A as option cause he's likely to raise that flop unless he has AK. So you're basically looking at a K/QJ/Flushdraw. If value is what you want, it's not here most of the times. A king will just call you of after the mild flop bet so you would have a hard time getting those kind of hands to fold. I would be very happy just showing this down and folding any bet on the river regardless if it's a heart or a Q/J. 66s is just a 2 weak of a hand on this board to get value from lesser hands imo.