cross-posted from Felson9's thread. thought this was interesting: a aspect i always have been awful at is adjusting my opening range against diffrent frequencies , so here is the question  which i do realise is pretty hard to answer since postflop frequencies will have a big impact on how we choose to play pre. but i feel that reading some theory on what why will help me become able to figure out this by my self in the future. Openrange 25-20 bb vsdefend/3b60/475/4100/030/2040/2060/20as for postlfop lets assume they play a controlled form of aggro.i would like to know generally what kind of hands are we opening and also some thoughts on why. hmm, i definitely think a lot of those frequencies you mentioned are a bit extreme...you don't see someone flatting 100% and 3betting 0% virtually ever, same for 60/4 and 75/4. but whatever, theory is fun, so i'll answer anyways...let's start with readless play...the population tendancy of an unknown player's oop frequencies is probably something like a total bb vpip of about 55%. 3betting approx ~15% and flatting ~40%ish...something like that. (~ = approximate). something like that. basically, the avg unkown imo is quite passive oop, doesnt 3bet bluff much, and doesn't 3bet shove nearly as many weak AX hands as a thinking player would. folding our sb is -0.5bb expecation, so our goal is simply to try to choose a play with each hand that has a better expectation than folding. since the avg unknown is passive, we have a low risk of getting 3bet. this means that we can comfortably raise a very wide range (~85-90%, slightly decreasing the closer we get to 20bb effective). while a lot of our range is weak, we will still be taking advantage of villain folding ~45% of his hands oop, and will also have plenty of +ev cbet/barreling opportunities postflop as well (the avg player is also quite passive postflop). an opponent who is folding >50% of hands oop:if our opponent is folding >50% of hands oop, it is theoretically optimal to raise 100% of our buttons. i prefer to raise something like 95% still - mainly bc I think showing your opponent a fold occasionally keeps them happy...even tho raising the bottom 5% of hands is theoretically +ev, i think it's extremely marginal at best (and if they continue a lot postflop, these hands can even be overall -ev to play from the sb still). if our opponent is playing 45% of hands or less oop, i'm definitely raising 100% though.an opponent who is very passive oop, flatting 65% and 3betting 20%:this opponent isn't 3betting us often enough for us to be adjust too much from our standard play, but he is flatting a lot wider than the avg unknown - so we need to make some slight adjustments probably.i would definitely continue to raise very wide vs this opponent, ~90%, as their 65% flatting range means that they have a bunch of weak hands in their oop range, will miss a ton of flops, so our cbet/barrels should work very well typically vs this opponent.after establishing reads, if we happen to find that this opponent is just not willing to fold much postflop (make sure you are being realistic about it though, so many players are too quick to call a player a 'station' imo) - then we can tighten our oppening range to ~75-80% (or even lower depending how stationy/wreckless he is post), check back more flops than we normally would with total air (maybe try delay cbetting some), and barrel more for value. tightening our pfr some means we have a stronger overall pfr that will connect to boards better overall - important vs someone who is not folding to our postflop aggression.an opponent who is 3betting us a lot, flatting 30% and calling 30%:since we have to raise/fold more often, i would tighten your sb vpip to ~80%. i refer to sb vpip instead of pfr bc:we should limp some vs someone that is 3betting us ~30%+. mid-connected hands that we would otherwise have to raise/fold to 3bet shoves like T9o, J7s, 87o type stuff are great hands to limp - and if our limp is raised they can typically limp/call well enough for calling to be > folding. so if we are limping ~20% of hands or so, that leaves us with a polarized pfr of hands that can continue vs a 3bet well and hands that raise/fold easily (and don't play great in limped pots). so our pfr will be something like ~60%, raise/calling the top 20% of hands or so.as villain's 3bet frequency increases more and more, your adjustment should be to:a) raise/call an increasingly wider rangeb) gradually tighten your pfr % (but not too much, would def prefer you just raise pretty wide still, and just raise/call a lot more...take some hands out of limping range like JTs/QTo etc and start raise/calling it vs a real wide 3bet freq...that way you have plenty of hands in your pfr range that can continue vs the wide 3bet freq - this allows you to still raise a wide, relatively balanced range preflop.i could expand on this a lot more, so if you guys have any more questions about this please ask.