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I had UTG on...

PF: 99-KK, AK/AQ

Flop: 99-QQ, AK/AQ

Turn: 99,TT,QQ, AJ/AhKh/AhQh

In my mind, I had him on TT though. That seemed to be his most probably holding. AJ shows up in my range on the turn. I think that is OK though. If you can't make any changes to the original range you put someone on, you'll run into trouble.

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I put the UTG on the exact same range, live passive players would play all these hands the same way based on my experience. This is why I said I think folding the turn is the right move. You are a 15-1 underdog against the UTG's range, and you are getting 14-1 pot odds to call, so just from this information alone you should fold the turn, but if you also factor in that the SB will have you beat 5-10% of the time since no read is 100% accurate, and that even when you do happen to have both these players beat you will still get rivered approx 33% of the time, Thats even more reason to fold this turn.

Heres a little more math to show that folding is correct, since you are a 15-1 underdog against UTG's range, you will be ahead of him 6.25% of the time. Lets assume your read on the SB is 95% accurate, so you will be ahead of the SB 95% of the time. Now the probability of you being ahead of both these players is (6.25% x 95%) = 5.94%, but even when you are ahead 5.94% of the time, your hand will only hold up 67.4% of the time since you will get rivered 32.6% of the time. So the probabilty of your hand being the best and also holding up is (5.94% x 67.4%) = 4%. If we convert this 4% into pot odds, you will need pot odds of 24-1 to call. If we assume you will make 4BB on the river if you hit your hand then you would only need 20-1 odds to call, since you are getting 14-1 to call, folding is the right move.