thin value or zero value?

Given V's description it's probably a flop fold and certainly a fold on the turn. Now that we made it this far getting better than 3-1 on the river, I don't know flip a coin but really should never be in this spot.

FLOP - don't bet 1/2 pot. Just bet 1/3 pot. Fold to his check-raise. He shouldn't be limp-calling a 5x raise OOP with Q6 or Q2. Maybe he limp-flats with 22, and he could easily have 66. Maybe he limp-flats pre and check-raises flop with AQo, or QXss. We're way behind his check-raising range here.

TURN - interesting card, reducing his thick value to one combo of 66 and three of 22. Starting to wonder if he takes this line with QXss. I probably still fold, but it's a closer decision than it was on the flop.

RIVER - hmmmm... interesting spot. Really doubtful he gets here with a better flush. I wonder if he'd take this line with KQ, especially KQss, or AQo with the Ah or Qs. I could see AhQs taking this line.

We have one of the best hands we'll ever have here. We really shouldn't have any flushes. His line is repping five to seven combos for value, but the 1-3 combos we beat are the least likely to take this line.

It's close, but if V is truly an uber nit, I think we should fold.

For V’s half-pot River sizing this has to be a raise. We can get called by KQ, KsXs, disbelieving queens (the front door flush missed, he can put in on missed spades).

This is a funny spot where we’d have an easier raise with a slightly weaker hand—that is, if we had trips (to block more boats).

But still, I’m not just calling a half-pot River bet when I hit a backdoor flush, even when it’s a baby flush (V can basically never have hearts).

I think a raise is just nuts here. We are certainly behind his range more than half the time and if we are behind we have zero fold equity. There's also not much in his value range that we beat and will call. What range do we beat that will call? Possible KQss exactly.

It's right on the border at equilibrium so too thin to shove against an ubernit. Probably closer to a fold than a shove. I don't think he has random 6x or much KQ (except for KQss exactly), so it's practically a bluffcatcher OTR.

Flop and turn feel too early for me to explo fold. An uber-nit is losing EV on a lot of later nodes and scenarios, not just us overfolding early streets. It'd be different if there weren't so many obvious bluffs to choose from. I'm probably just being an explo nit though...

EDIT: Definitely just being an explo nit. There aren't "so many obvious bluffs to choose from" other than the FDFD. Other than that it's just (partially blocked) combos of GSSDs.

On the flop I snap fold to the check-raise with 5-high, a gutshot and a backdoor baby flush draw. We are losing to his bluffs.

People construct their BvB ranges so differently that it's hard to pinpoint a range, especially live (do we expect QQ to limp-call? KQ? Baby spades?)

Turn card is pretty neutral (flush draw vs card removal vs RIO/drawing dead) so if we haven't folded the flop then folding turn remains an option - again this may come down to whether you think there are hands like AA here BvB)

River you have improved to a bluffcatcher (OK KQ). Calling seems fine but if calling is only marginally +EV when you go runner-runner then something was seriously wrong with earlier streets.

I am a bit confused - why an 'ubernit' could play Q6s out of position? I don't define my self anyway near a nit but I don't play Q6s at BB this way.

I can't really picture any villain being a nit + playing Q6 + playing 62 + possibly just calling the straddle with QQ / KQ OP + not raising flop with spade draw 90% of the time, so I will try to not factor in any exploitable part of the villain.

I am not raising the river, AP 70% call 30% fold.

Fold turn! Drawing on a paired board against someone described as Uber nit is asking for trouble.