Been taking some shots at 200NL FR recently and the biggest difference I'm noticing is that I'm getting 3-bet pre-flop a lot more. I've been folding the vast majority of the time, except once when I 4-bet shoved with TT on the button and BB showed KK and a few times when I've called in position with suited broadways or a mid-pp.

Any advice for when I should be cold-calling 3-bets or 4-betting? Should I ever 4-bet and not shove, with 100BB effective stacks? How many times does an unknown villain have to 3-bet without showing down before I assume he's a light 3-bettor? How much should my ranges change in and out of position?

I know I'm asking for a master's thesis here, so answer whatever parts of this you want...