100/200 game
Preflop UTG (500bb deep) reg opens for 500, the recreational player at the table calls 150bb deep, I call with Q8s on on the Button. All other players fold.

Flop: Tc Js 5s (pot 1800)
UTG reg check, recreational bets 600, I call, UTG calls.

Turn: 9s (pot 3600)
Utg reg checks, Recreational bets 1200, I raise 5500, utg reg reraises 20,000, recreational folds. I call.

River: 7c (pot 43600)
UTG reg thinks for less than 10 seconds and goes allin for my effective stack of 70,000. I decided to fold.

My thinking process at the time was that with the recreational player in the middle that could have anything the reg raises to 20k on the turn is very risky with a bluff.

But on the river the story doesn't really add up. On the flop we are all deep stacked. In hindsight I think he would cbet a A high flush draw on the flop. (He plays a high frequency cbet style of play)

Another point is. If he has the absolute nuts, he obviously could go for max value and just overbet jam for a sizing that would be hard for me to call. But if he wanted value maybe a sizing like 15-40k would be a better play?

I've played him a bit, not a ton. But in my mind his image was pretty solid and his calling down range is tight. (It is easy to get him off of hands) But i've never seen him run big bluffs before. Also at the time if I folded I would have been up 10k for the day, if I called and was wrong I'd be down 60k for the day so I think being this deep (I did not intend to, started off session running bad and recovered to a deeperstack). So I opted for the "safer" option and mucked.

How would you guys have played this? I mean every street this deep could have played differently. Preflop could have 3bet, flop could've raised, turn could have folded etc. Let me know what you guys make of this hand? (also I know what he had, won't reveal it atm)