Live $2-$5 hand from Foxwoods Fri night.

History:
Hero (CO) - been there for about 5 hours now, only one player has left the table. Busted a short stack on first hand with AK, then proceeded to go 4 hours without winning a pot before doubling up with J's and making a hero call against a stone cold bluff. Stack is about $650.
UTG - pyscho maniac. Shown down $30 preflop raises with A4 off or 56off in EP. Has been caught bluffing several times and is on his third buy in. Stack of about $350
MP - described by a friend of mine who is a pro here that he is "the tightest player in the casino". Hasn't really played many hands at all, probably less than one per orbit. Stack is about $600.

Hero: 6c 8c
UTG raises to $30, MP calls, Hero calls.

FLOP: 5h 7s Jd
UTG CBets $50, MP thinks about it and seems to begrudingly call, Hero calls.

TURN: 9d
UTG fires $100, MP InstaRaises to $250, Hero...
Now I'm pretty much putting him on a set of 9's @ this point. 8-10 is not even in my realm of thought as there is no way he'd call a gutshot on the flop so I'm positive I have the nuts @ this point. If I trust my read, I can either take the chance and smooth call PRAYING the board doesn't pair on the river (meaning I'm screwed) or a diamond doesn't come (Action killer) or shove to make him pay if he wants to draw to 10 outs. Def want to extract maximum value here, what do y'all do?

Yeah you can shove at this point, IMO

If UTG is that crazy we can't rule out T8, but unlikely

MP Nit probably has a set... I wouldn't agree that it's a set of 9s though, it he is truly the "tightest person in the casino" he probably folds 99 against a c-bet with one over and you still behind him, but even if it is a set of nines you're still in good shape

So MP may have a set of Jacks or sevens, or an over pair... maybe not, an over-pair has to 3bet preflop against such an aggro utg

so against diamonds, a set, two pair, any of those you're ~80/20... nice hand sir

Firstly, we have to consider what UTG will do if we call or raise. He's shown down some absolute crap hands, but did he double/triple barrel bluff with them? I'm inclined to think that even a maniac has some connection to the board here when he fires a second shot with two opponents still in. Air is still part of his range, but I'd also include Jx, A7, K7, and two pair.

Secondly, MP is going nowhere in this hand. He might have a flopped set instead of a turned one, because I often find that a "begrudingly call" from a capable villain means a slowplayed monster. Either way, he's in regardless of what you do. If we want to extract max value though, we'd like to have both opponents remain in at least on this street, if not all the way.

Lastly, what river cards really kill your action? I disagree that a third diamond does. It's impossible to know if UTG has diamonds underneath to go with whatever else he's playing, but I'm certainly not worried about it. Especially since he can't have the most likely flush draw, which would be Jx of diamonds. If the board pairs yes you're in trouble, but since MP is never folding I don't think you can try to make him pay. You're also in position, so MP is going to bet big on the river no matter what.

With all that in mind, I think calling is best here. It gives the best chance for UTG to at least call this street, and who knows, he might shove over, then MP instacalls and you fist pump. If UTG calls and then checks the river, then with any non paired river card MP bets big, you shove over, and profit. This way, if you really really trust your read of a set, then you also lose less when you get unlucky and the river pairs the board, if you can bring yourself to actually fold the straight.

I thought about MP flopping a set, but from what I've seen he doesn't slowplay at all and probably would have repopped UTG on the flop. Have also seen him call down with second pair when he trusted his read and was right.

UTG would not have 8-10 here. He's played alot of suited gappers and non suited connectors, but his style was to limp with them and then call raises to see the flop. Honestly I'm not giving him credit for any hand higher than A 10 at this point.

So anyways, I end up thinking for a minute and shove all in. UTG instafolds and MP really goes into the tank. After about 3 full minutes he says "I'm such a nit" and shows J 9 suited for top two then folds.

You played the hand well, just unfortunate you ran into the only player capable of laying that down at the table. Flatcalling sets off too many alarm bells.

I'm not saying OP played the hand poorly, as there is little wrong ever with shoving over a raiser when you have the (basically) nuts. I would've flat-called, as I stated in my post, but that's not what I'm getting at here.

I disagree that he was only unfortunate to "run into the only player capable of laying that down." If I'm MP Villain here, I know that I've shown strength by raising the turn with a connected board. Then when the player after me 3-bets cold....this is NEVER a bluff. He's saying he has a better hand than me, and I can't see even a lower two pair 3betting here in position. Since hero overcalled on the flop, if I were villain, I'd put hero on a set. The straight I wouldn't have seen, but regardless of that, I think the read that hero has villain beat here is actually quite simple.

Calling might set off alarm bells, but it gives UTG the chance to stick around or maybe make a foolish move, and there are lots of hands that Villain can put Hero on when he flat calls that Villain would still think he was ahead of.

I'm capable of folding this hand, as are many posters here. Point was that, especially live, many players cannot make this laydown. Larger point was that OP shouldn't really question his line because it's capable of extracting maximum value (other ways to play it exist, of course, but he already seems to know that).

I think it's sort of dumb to flat call. I just put him all-in when he raises the pfr on the turn. Most players won't fold any hand in their range of raising the turn, so I HATE a call since we basically have the nuts. I think it's sort of silly to call and have no idea where you are at on most rivers. Just put 'er in.

Plus the dude has half of his stack in. It takes a lot for someone to fold top two/set/any two/huge draw after raising the first guy on the turn. You just got unlucky that he is, as he said, a nit.

My reasoning for flat-calling did not involve MP villain at all, to be honest. I thought the money was going in regardless from him, as I stated in my first post in this thread. I suggested the flat-call to get UTG donk to call one more street or to make some foolish all-in move.

"Nit" widens his range to suited one-gappers against the maniac.
"Nit" makes the right call on the flop with the best hand.
"Nit" lays down when he's beat.

Well played, nit.

The only reason I flat the turn if I know the UTG maniac is gonna shove when it gets back to him. I know that your read of UTG = maniac, but him shoving over a r/r and a flat call requires him to be a whole new astrologically high level of maniac that is pretty rare to find anywhere.

Worrying about T-8 is out of the question as the possibility of MP having is small because his tight nature. Worrying that UTG has it is out of the question too because there are so many other random marginal hand combinations that you have beat. Shove it.