even if you don't know the opponent's hand, you can still assign them a range of possible hands based on their table play, or just a generic range if you have no reads.
so, let's say you're facing a very active/aggressive raiser to your left who 3-bets ~ 2x per orbit, likes to barrel postflop, and has shown down some bluffs. you are dealt KQs and it folds around to you. you raise, he 3-bets. what is a range we can put him on? based on our limited history and assuming a full ring game, he is 3-betting preflop 22.2% of the time. assigning a generic range based on the top 22.2% of starting hands we have:
let's see how our equity holds up. preflop:
now, let's imagine a hypothetical flop. for simplicity's sake, we will avoid flush possibilities:
we're in good shape against villain's range, but he continuation bets on the flop and calls a raise. we see a turn card:
villain fires a 2nd barrel. what's our play?
unfortunately with this type of LAG player, we can't narrow his range all that much. this is why LAG players are tough to beat---they make you gamble with higher variance in order to defend your equity. we know he could have hit a set or a straight, or turned a stronger pair. after all, he did call the raise on the flop. we also he know he could have a weaker pair, he could be semi-bluffing a gutshot straight draw, etc
anyway, this is just to highlight a spot where i think people give the villain too much credit. yes, our equity dropped on the turn, but it's really important to consider villain's entire range rather than automatically assuming he made a better hand by the turn. LAG players are often skilled at reading players, especially OOP, so the likelihood that he called the flop raise based on pot odds and is bluffing the turn---knowing he can likely scare us off the hand---is still pretty decent.