Any opinions on the best way to go about constructing ranges to flat 3bets and 4bets? I'm talking about OOP, although any thoughts on IP would be welcome. Should this be as flexible as the opponent is in terms of his 3bet or 4bet range? To take extremes, some will 4bet only AA, some will 4bet 10% of their BTN open range. Or can they be pretty specific versus many different opponents? Flatting 4bets oop has been a bit of an unknown for me, and not that common in 3bet situations either, which is obviously losing value. I 3bet, IP Villain 4bets, I'm there with JJ, 66, AQ, half lost and end up spewing off stacks or folding too lightly. or CO-D I 3bet/c4b w/KJs and watch me get towned on 6xx or Kxx. Not sure there is any videos on this subject? When I've got more insight on ranges, I can get working on some trees etc.

Thanks