Facing a 3bet

So we want to know; should we raise, call or fold? Also, if we raise, ie 4bet, to what size do we do so?

Variables: Absolute positions, relative positions, postflop PSR, tightness, postflop range consideration.

In position, our range for 4betting should basically always be polarised, ie there's very little point in 4betting JTs virtually ever. Playable hands like this are always flatted, and the range constituting 'playable hands' depends most importantly on the player's tightness in that position and the postflop PSR. We must resist the urge to flat very speculative hands when we get deep though, as a range constituting too many 96s and the like will simply be a very poor one postflop. Such hands can be flatted though when deep, but we need to ensure we have a very good handle of his tendencies. For example, can he ever fold an overpair to a raise and bet turn line? Does he check flop a lot and give us free equity? In general though, shy away from these flats and look to use them as 4bets.

Still in position, if we're deep then find some playable 4bets, maybe even some stronger playable hands such as J9s. We want range coverage, so we automatically get given AK etc, so we need some QJT9xss type hands, therefore Q9s, J8s are good candidates.

Sizing, we want to manipulate the PSR in our favour if flatted, which generally means we can go small flop, small turn, shove river, or on different boards big on the flop, shove turn. Just by thinking ahead, we can decide this size.