Your assumptions are correct, button should be opening wide and I would be 3 betting wide from SB, playing a 3bet or fold strategy. His 3x sizing is large but many regs use this size so it doesnt mean too much.
My 4x 3bet is also fairly standard, can't agree with the below that 16-17 is normal. I rarely see 3bets that large.
So the standard 4bet size would be to something like 25-28bbs. I.e. a size where he can have bluffs that fold to a 5bet shove. When he makes it 48bb it's clear he is almost never folding. Not much point calling and playing with a 0.5 spr oop, so it really is a case of shove or fold.
Then it's trying to work out what his range is and whether we have enough equity. I really havent seen this type of sizing very often so it is tough to range. The problem is we only just have the equity v QQ and lower pairs, we are in bad shape v KK and crushed by AA. So it's really how often he could have unpaired hands like AQ that we are in good shape against.
Framed another way is the 4x 4bet a sign of strength or sign that he wants a fold. Its certainly a sign he is a fish!
If I have no stats on someone it's true they are more likely to be a fish, but as this was on PS and I dont play there much now, I didnt automatically assume they were a fish (until the 4x 4bet)
