I need heeeeelp playing in this situation
The obvious solution to this problem would be to leave or change seats, but let's say, for the sake of discussion that changing seats or tables is not an immediate option. Maybe there's only one table of your game, nobody's getting up, and it's full with a wait list. Or maybe it's one of the first few levels of a slow structure tournament, and your table isn't scheduled to break on day 1.
Assume this is for deep-stacked play, 150BB+
There's a decent aggressive villain with position on us who likes to mini 3-bet us with a wide range. He plays well post-flop and also understands pre-flop raising wars, but he's loose and aggressive enough that his range is a little unbalanced and more skewed towards bluffs than value.
For example, if we make it 3X, he'll make it ~7X
If we make it 4X, he'll make it ~9X
Obviously, sizing is small enough that we're not going to fold, especially since we know he has a wide range. But none of the options are particularly attractive either.
If we flat every single time, we're always OOP without the betting lead in a bloated pot, definitely a disadvantage
Our counter-move, which is the 4-bet bluff is less attractive against small 3-bets than it is against normal sized 3-bets, because we don't win as much if he folds, and there's still a decent S/P ratio left if he calls.
If we 4-bet small, he'll often call in position to make a play post-flop.
If we 4-bet large, we're risking a lot to win a little. For example, if we make it 4X and he makes it 9X, we would have to 4-bet to at least 25X for him to consider folding. And he knows how to 5-bet light if we 4-bet too frequently, so we're really risking 21BB to win 9BB.
It goes without saying that we should tighten up our opening range. But in addition to that...
Some of the counters I'm considering are:
a.) Start flatting and donking the flop with our cbet range, just as if we raised and he called (he might still be annoying if he's aggro post-flop)
b.) 4-bet with a depolarized value range and be prepared to stack off very light (meaning with hands like AQ and 99) if he 5-bets bluffs unbalanced and too frequently (rather high variance, but you should be getting it in ahead of his range more often than not)