All this talk about nits gave me some motivation to study a bit about how to exploit them with pio, here it is:
It's very common for nits to go tighter than monker pre-flop, so BB adjusts to going tighter than usual, that idea looks right, but vs a tighter pre-flop range, what changes it's that BB has to defend different hands, maybe even more hands overall if you think for a bit.
Hands that underrealize vs tight ranges: KQo, A9o, ATo, JTo
Hands that overrealize vs tight ranges: 56s, 53s, 23s, 74s, A4s, 96s
The idea here is all about board coverage: whenever IP opens tighter than usual, it means he will be dropping those weaker SCs pre-flop, so his range will be stronger on higher cards, but weaker on medium cards and also on small boards too. So our strat vs that is to give up on high boards and punish them very hard on medium/low boards. Remember that polarization pushes EV more than overall equity, it's more important to have at least some nutted hands in our range than having stronger hands on average, also this effect is increased when IP plays its value very aggressively and treats 246 boards like bricks (which it should be somewhat true in some spots), but when OOP is playing less KTo and more 24s type of hands, things can get out of control for IP very fast if he doesn't realize he has to play more passively because of the lack of nutted hands in his range.
This is how IP should play the flop with monker ranges (MP vs BB):
EVs are very close, as you can see, IP has to play very cautiously in there, having a lot of big overpairs isn't very useful on a board like this when OOP has a lot of straights, 2p and pair+draw.
Now I've changed both players' ranges to look something closer to reality: IP going tigher(but adding 22-55, because nobody folds those pre) and OOP overfolding broadways and overcalling SCs and low hands. As you can see, IP has a range that is almost 50% smaller than monker, with more sets on that texture and the EVs are almost the same. Look at how crazy it is, IP has almost 2x more overpairs in that spot and this is what is happening. Sure, OOP has less KQ which plays badly on these textures, which makes up for more EV. One could say: yeah, it's obvious that overfolding higher cards will give OOP higher EV on lower boards, but his range becomes ****ed up on higher boards, OOP will get crushed in there and will overfold.
The thing is:
I believe there are some good nits, I've heard about some nits doing well at 500z on 2019, but they are strong regulars that decide to play tight because they think it's higher EV, they believe people don't overfold pre and might even capitalize by overbluffing turning hands into bluffs into some tricky spots postflop with hands they shouldn't, but since they're tight few people could realize they're bluffing enough in some spots.
But overall the majority of nits play insanely bad, just look at the example above, it's so easy to play well vs someone playing tight pre. Sure, rake is high, but when you know theory and your opponent doesn't, then he will make compound mistakes throughout the hand, which can easily compensate the rake.