Button is 18/`17/10 in 350 hands. Thoughts on the whole hand river decision are appreciated, thanks.

CO: 78.5 BB
BTN: 122.38 BB
SB: 87.16 BB
Hero (BB): 100.4 BB
UTG: 59.88 BB

SB posts SB 0.5 BB, Hero posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has Q K

fold, fold, BTN raises to 2.2 BB, fold, Hero calls 1.2 BB

Flop: (4.9 BB, 2 players) 9 6 Q
Hero checks, BTN checks

Turn: (4.9 BB, 2 players) 2
Hero bets 2 BB, BTN raises to 9 BB, Hero calls 7 BB

River: (22.9 BB, 2 players) 4
Hero checks, BTN bets 33 BB, Hero?

I’d call

My inclination was that we'd rather stab big on this turn when we bet and GTOwizard seems to agree. As played if you think he's decent I'd call river since everything bricked. If he's bad and therefore likely imbalanced just fold

Pretty easy fold. Most underbluffed line ever

lol, running a sim, forgot to add our actual hand to our calling range since I'd always 3bet pre
my BB 3bet strategy sucks, I'm sure mixing KQo is fine

I like the turn stab, but I would've gone with a larger size.
Getting raised here is weird and I never know what ppl are raising with in these kind of spots, it's hard to find bluffs so are they only value raising?
I wouldn't play a single combo like this, checking behind flop and then raising turn, so I can't imagine why or with what people do it.
I think our hand is too strong to fold here, so I'm calling the raise.

River is an easy fold for me, I'm not calling overbets with one pair.
My sim thinks it's a 100% call though.

Yeah I expected solvers want us to call here, but I agree on folding in practice. This line is so underbluffed, especially by a 18/17 nit. Against a more creative player we probably have to call though.

I could see BTN doing it with 22/QQ/Q2s/Q9, or some sort of club draw that gave up flop but picked up enough equity to try bluffing a turn stab (Ac7c, KcJc, 54s, 43s, 53s, etc). You’re also supposed to be mixing checks with stuff like JT and 87 and T8 occasionally OTF. People will also take this line with stuff like 99/66 sometimes, even though they probably shouldn’t.

River is a call in theory all day long, since this is probably close to the best blockers we can have, since blocking QQ/Qx two pairs is really nice, and having a J, T, 8, 7, and 6 are all bad since they block busted straight draws.

Notice how your sim calls/raises A2 pure, since villain is supposed to either have air or nut hands here, and blocking 22 is super important. Also notice how sim calls some A6 but no J9 despite absolute hand strength (we block too many bluffs with the J and villain isn’t really supposed to slow play 66 or 99 OTF). But I guess blocking QQ/Qx two pies is important enough that we’re OK with calling QT.

If we’re folding river it’s because we expect villains to be super underbluffing, as doodoo suggested. I’d speculate this spot may be different than most other x-r-b spots, since there’s so many combos that picked up equity OTT and busted OTR.

Really cool spot, thanks for solving

+1

Thanks for the feedback everyone. This was a weird line and one I don't believe I've even seen since back playing a lot. It just felt like a turned set of deuces, on the flop he didn't care and come the turn he's C/R and overbetting river. I did wind up folding so not sure what he had. I ran it through GTO Wizard and it was a pure call there as well, but as you guys said IRL it's a very underbluffed line. Very interesting sim and spot for sure.