btw this is on bovada so we can't assume he's a fish because he's not full stacked, just an unknown reg

Easy bet imo. He has some JJ, TT, KQ and he might even hero AK with club blocker. I would go on the smaller side though since its hard to have bluffs.

I think this is a bet, agree with saulo about a smaller sizing.

I don't think he's betting Qx here on the river checked to, especially since his Qx hands that he checks back otf will often be with medium/weak kicker looking for a easy showdown, even AQ might check back if played this way since he might think we are checking to jam our strong value hands.

Also he's not calling Qx if you check jam river so by betting we assure we get value from those hands instead of him checking back like a QJ/Q10-type hand.

I'm betting and lol-folding vs a ship. Just bet small. This is a spot where he's probably checking his SDV and just never bluffing. He also still has QQ in his range so x/c kind of sucks.

Why 4x open? The 3b is also quite big... Any reads and possibly just fold this @ 100bb depth.

I don't understand why you bet so small OTT, but maybe sizings are messed up here as well? I think 75% pot to 100% pot is better with your value hands and I usually try to avoid giving away information against decent regs. I don't think bet sizing matters a lot, but I think going smaller than 2/3 pot loses you a lot of EV.

I don't think either turn or river connect well with villains check back range, so even some Qx might be able to valuebet (less need to trap to "defend checks" if that is something we need to think about). I think you can treat the board pair as a blank and heavily discount flushes from villains range. Therefore I think there is less value in XR because villain will check back very often and not call the XR a lot with worse flushes (because he usually bet flop with FDs).