Villain is a bad reg, plays 19/16 over 5.2k hands and calls 3bets OOP. I normally have a plan before i 3bet this, but this was an old hand so i can't remember what i was thinking at the time, other than, he calls 3bets OOP so i should punish this. He is opening 26% from CO.

Basically, stats say he folds to 3bets 55%, and has 13% 4bet.
But, my notes say, so far he has folded 4 times, called 4 times, 4bet/folded 3 times, and 4bet and i folded 3 times(i dont note the instances we get allin with premiums).
So in my notes he seems wacko, but his stats seem quite nitty. I don't know which to trust?
Im thinking 13% 4bet is quite low? Shouldn't it be closer to 25% if he is playing optimally?
Though, i don't know how him calling pre-flop too often messes with his 4bet%s...

What would you guys do here?

$0.50/$1 No Limit Hold'em Cash, 6 Players

MP: $106.50 (106.5 bb)
CO: $100 (100 bb)
Hero (BTN): $138.92 (138.9 bb)
SB: $130.40 (130.4 bb)
BB: $36.63 (36.6 bb)
UTG: $264.04 (264 bb)

Preflop: Hero is BTN with A Q
2 folds, CO raises to $3, Hero raises to $9, 2 folds, CO raises to $22, Hero?

I shove

Yeah shovels here btn vs co.

Although if you think he's just rando and will start to 4b PP's to get in and is still 4b folding, then I like flatting more and pooping on his range.

13% 4bet is actually pretty high. Something like 5% would be considered low, and 25% would just be straight maniacal

I think you're thinking of 4bet range.

Biggest thing to mind here is that we are on the BU, the most profitable spot in poker. By 3betting here while we are on the BU we basically push out the 37bb player, who either is a fish (then we want him in the pot, and flat PF), or is a shortstacker (who can be induced to shove really light in a spot like that). Also the SB is 130bb deep with us, and is still left to act, which can make this spot really awkward, what is our plan if he calls OOP, or if he cold 4bets.

3betting AQo here is in my opinion giving up our possitional advantage, and our card advantage vs what you say is a bad regular so i assume we have skill advantage. We disregard all those advantages and benefits, for the reason that we think we can get more value by his flats OOP (but we don't know what kind of hands he flats with), and we don't know what to do vs a 4bet (we don't know what kind of hands he 4bets with).

Therefor 3betting AQo for value here is only good, if this player flats with stuff like suited A's, and stacks of 3bet pot with any TP, or that we know he 4bet bluffs a ridiculous amount, or maybe 4bet/calls stuff like AJ or suited A's whatever.

So I don't believe with us being readless on the guy, besides from a few stats (which could mean anything), that we can get more value from 3betting here than we can get from flatting. Remember it is our first hand on the table so there is no dynamic with him that induces him to 4bet bluff wide, or make us think he might do it more. As played if i had missclicked 3bet here, i would just hit myself shove since he has shown to be able to 4bet/fold, and is likely to do that the most in this spot. However I still do not like this withouth establishing any kind of dynamic in this current session, maybe never in this spot.