There is more than one type of fish and you need to be able to categorize them pretty quickly at the poker table in order to maximize your expectation.
Passive Fish – There are two types of passive fish.
Type 1: The fish who doesn't fold to anything pre-flop but folds to many c-bets and 2nd barrels. With this type of fish you should basically be figuring out the absolute smallest amount it takes to isolate them at your table, and then ISO often. Since they won't fold pre-flop you don't want to bloat pots with vulnerable holdings, but you do want to isolate with those holdings since you will either be ahead in the hand or you will win it post-flop through solid hand reading and bet sizing.
Typer 2: The fish who opens many hands and backs down to resistance. This one is much easier – just 3 bet them all day long and fold when they 4 bet. Don't level yourself into thinking the fish will make adjustments. Honestly it's not worth getting it in light only to find out they had AK+ and you talked yourself into thinking otherwise. Fold to the first time they 4b but if they continue to do so, make sure you are the one adjusting after this new piece of information.
Aggro Fish – I think there are two types of these two and once again they are pre-flop and post-flop.
Type 1: For pre-flop aggros you just need to muster up the courage to rip it in with hands you'd otherwise be folding. The types of fish won't call you correctly because they'll overplay things like A5o and so even when you're ripping it with KTs and J8s your hands will have sufficient equity vs. their range.
Type 2: For aggro post-flop fish you need to figure out if they are overplaying their hands or betting too big with strong hands and folding everyone out of pots incorrectly. Once you've seen a couple showdowns you can then go into call down mode against the overplaying fish and you can get away from your medium strength hands very easily vs. the fish who pot bet their nutted up hands.
Just remember that there is more than 1 type of fish so playing the same style versus each one is not going to yield the results you are expecting and will more often than not lead to you tilting and punting stacks.
hawkeyeK9
Good post man. It is so important to label your opponents and understand there playing style in the present moment and constantly be adjusting. Good insight on just giving them a broad label as a fish is not enough.
martyfm
how do you figure if there overplaying there hands???pre flop or have a strong hand??how many orbits ??