Point of departure here is that a regular in the 2/5 game (who used to lay down almost always) has now started floating me. So, I thought I'd explore possible optimal responses.

First off, I'm not sure yet just what he's going to have here. I'm not sure whether he'll call my raises with KQ or not. I'm pretty sure he will with AQs at least and for sure any PP, but some details of his range are definitely relevant anyway.

I'll start off with situations where I'm in position, and I'll just assume a raising range for me of JJ-AA and AK (I think SC raises are dodgier against a floater and need to me at least more rare).

Here's actually the line I'm thinking might work well with position: Go ahead with the CB, then check a missed turn (getting a free card to spike it) and some monsters (like big sets or nut flush). Then when he bets the river, go ahead and call with JJ on a K-high board (hence my question of whether he's in there with KQ), etc. Basically, lay down completely missed AK there, call with big pairs despite overcards, and raise the river on monsters.

Also, if the board doesn't look too bad, checking behind on the turn (and calling the river) with a real overpair is probably a good idea. On that one, my attitude is more "sometimes"--depending on board texture.

Now for OOP: Here, I think it's probably a good idea to fire again with a big pair even in the face of overcards. Check-fold on missed AK, and CR on a mix of overpairs and monsters. On AKs with flush draw, I think it's worth firing the turn again since there's fold equity at this point (he doesn't have the read that I'm only firing the turn on fairly weak hands on this strategy--namely missed AKs and big pair with overcards showing).

Also worth noting here is that I'm not really sure about how this guy is playing sets against me at this point (I actually can't recall even having him set me up to this point, although we've played quite a bit together). So, I don't want to get in too deep in situations where that may be the case. And, as noted, I also am unsure what he's doing on some decent big card hands.

Thoughts?

Your overall postflop strategy seems too nitty. With a raising range of {AK, JJ+} you can fire 2 barrels blind. (I am even unsure if it is a joke or an optimal strategy.)

In position you mostly need to show aggression at least on 2 streets postflop, if you check turn raise river. OOP with this range you can fire 2 barrels a lot or check-raise turn.

Basically, in the described strategy you bluff only on flop, i.e. CB when you don't connect. I would also start floating you every second hand in this the case. Fire some 2nd barrels and he'll have a much tougher time playing you. Instead you are going into a tighter mode.

VS Floaters I like to CB flops that have potential for a second barrel more, and other flops less often.

A flop with good 2 barreling potential would be J 6 4, or 9 3 2... with these ones when an overcard spikes the turn you can fire a second barrel with good success. Also QQ5 flops where he'll be a non beliver till you 2nd barrel, or rarely 3 barrel.

Seriously just 2b a whole bunch more and check call turn with TPTK or overpairs if the boards not to drawy, so when he is floating he is more often giving you value from your induced bluff.

If you get busted 2barreling then he may be less inclined to float you in future.

Don't wait for premiums to check raise him OOP. If he's floating that much his hands are very likely to be weak. He won't be able to call. A few of those he will stop betting the turn behind you out of fear.