but we didnt know if the BB is a fish or a tight player until the river aint we?
Not knowing the player I wouldn’t have played it that way.
Lets analyze it.
Preflop MP we are looking at AQo (if we assume we don’t know the player) so we place a standard raise 3x. everyone folds but the big blind.
He is getting 2.25:1 for a call. And he calls. We can discard QQ+ (sometimes also JJ) because he could have reraised. Also AKs or offsuit. We also can discard small suited connectors such as 23s till 78s and non suited.
Now, what can call here? Small till middle pairs (22-1010), high suited or off suit connectors J10, JQ, KQ. Maybe some one gapper like KJ, AQ, Q10, or a double gapper K10, AJ and A10. I can keep in mind some weak A like A2s till A9s type of hands depending on what type of player we think we are facing.
On the flop he donkbets for the minimum $ 80 (1bb) and the original raiser decides to just call to try to gain some chips later on. Not a bad move but it doesn’t tell us much about the players range so maybe a reraise should have been better. We can discard hands like AQ, AJ and A10 (the bet size would have been bigger).
Then the turn is a 7 and the BB leads out. So he has fit the flop in some way because he leads for more or less for 1/2 of the pot.
Lets discard something here: 22, 33, 55, 66, KJ, K10, J10, small and middle suited connectors such as 23s till 10-9 (a small seven isn’t good enough to raise here so discard them), 88-1010 would have called here instead of leading out also because hero could have played tight a weak ace.
We are left with Q10, KQ, QJ, 44, 77, and some type of weak ace.
Hero reraises (not a good sized bet in my opinion) and he calls so we could say he has hit very good. At least a good Q (KQ, QJ), 2 pairs like A4, A7 or a set (44, 77).
River is another 7.
BB leads out again with, I assume, most of his chips. He is willing to put most of his chips with another 7 on the board. Why? Norman Chad would say that a 2 changes nothing but a 7 can.
Does he really want to risk everything with a weak Q (KQ, QJ, Q10) or a weak A (A4 isn’t good anymore)?
It leaves us with 44 or A7 almost 85-90% of the times.
I would have folded leaving myself still with 18bb (still playable considering the blinds are small and there are no antes).