Reads, history, Aggression stats will help in these spots. There are some guys I would snap call all three streets and there are guys I am mucking to the turn barrel and there are some guys I am folding the river to. Hard to answer.

Against a passive guy, I am finding a fold somewhere and against a highly aggressive player I would probably call down. There are 4 pairs that you beat......8 pairs that crush you (over pairs to your JJ, FH's, Quads).......one you tie with obviously. Is he the type to 3b A5-A2? If you put all pairs, A5, A2 and AKss (missed draw bluff) in Pokerstove, JJ is a 60/40 dog, QQ is closer to 50/50 (for analysis sake only)

After all of this, I have decided to stop playing JJ :)

i dont think you need to open 4x from the CO unless ppl are realllyyyyy cally in your games and you wanna get some extra value. I see some pros opening 2.3-2.5x from CO, i usually open 3x. I think if you open 4x some people might read into that. I think ur open sizing depends on how often the BTN and blinds are calling or folding or 3 betting... but standard is to open 3x or 2.5x i think.

BTN 3bets generally speaking are lighter, so you could consider 4 bet GII preflop. But idk in your stake what peoples 3bet ranges are, but generally speaking since people open CO light, 3 bets will be lighter so getting in JJ preflop in this spot is fine against someone you dont know and if your beat here thats a cooler, all this being said if you have have no reads on your opponents.

Flop call is perfect, turn call is okay but you can consider folding depending on how aggressive your opponents are. I think on the turn generally speaking you're looking at TT+ or a Ax of spades or a suited connecter. With no reads, I might find a fold on the turn but its a hard fold. I dont like making big folds vs people i dont have reads on however your villain is taking such a standard line with an overpair its likely you are beat, and the key to knowing your likely beat here is that he 3bet you preflop. Even some of his 3bet bluffs got there (any suited connector with a 5, and he can have all sets). I think I would check if hes multi tabling, if you cant find him I think its a fold. If hes multi tabling u can call here and call any non flush or non A K Q river.

OTR, as played, some aggressive players will barrel off here with there missed flush draw. But in this spot, I think the key is that your villain doesnt know you. So that being said, since you called him twice, if hes any decent he should know you have A6suited, sometimes 77-99 but that might have folded the turn, and you can have TT and JJ,. If you had QQ-AA you might have 4 bet preflop or raised flop so those are alot less likely. If you had a straight you most likely would have raised that on the turn in his eyes so its unlikely you have a straight. If you had a set thats now a full house i think your villain expects you to raise that on the flop most of the time, so you having a full house here is unlikely. And generally speaking I think in his eyes if you had a flush draw you would have folded turn but I could be wrong. So since he knows its likely you have a relatively strong hand, it would be quite ambitious to make someone you have no experience against make a big fold, making it less likely he is bluffing here. Hes just taking such a standard line with any overpair, so i wanna say its likely your beat here. If you encountered other villains in your stake barreling off a missed flush draw in this spot then you can call here. But with no reads IMO its a fold.

Overall its not a cooler.. its just a tough spot. Against someone you dont know, hes just taking such a standard line with an overpair i think you can find a fold on the turn maybe or definitely OTR.

Thanks for the feedback.

FWIW, this is at a readless table on Bovada so I guess I'm looking for input on what the theoretically sound line is.

You can exploit the player pool tendencies by folding river. This line is 95% of the time QQ+, with very few occasional spews.

4x open and 12x 3bet ? this usually indicates alot of strenght.

4x opening the limping mp.... and 3x bt vs co should be Standard

I don't mind opening 4x when is a limper, I think is correct. Calling the 3bet with JJ also is fine with me unless is a really passive villain that never 3bet, even in that situation if villain is deep is an instacall for me, the Turn I think is the spot that you should evaluate if your hand is good enough. A good read on the Villain it will give you the answer. If is an unknown folding the turn is not a drama. Patience and better spot will come up.