ATs SB 2 callers complete or Iso?

I would normal raise here, but I don’t think a complete is bad ether. It’s still a decent change you will play a big pot OOP and I don’t think they would fold to often here. So You need to make big raise of at least 5bb to get it work. Of course it’s always nice to have the initiative during the hand against hopefully only 1 caller.

As played the river play is interesting and I don’t think a passive fish would bet with less than top pair. So I would fold here without reads on him he’s capable of bluffing.

Cheers,
SDK1987

First of all, I think you should ask yourself whether you would Isolate with AJ+ here or not. I think your answer will be a solid "yes" so that ATs makes not much difference in terms or preflop equity (62-65/35-38% for A9s+/1 limper range) and I think you must be more aggressive to protect your equity coz against 2+opps you are gonna be less than 45%.
I don't think that initiative matters against passive players (correct me if I am wrong) coz they just stick to "what is my hand" constanta and discount many other factors. Anyway, postflop, against a passive player like BTN you either hit and try to get money from drawing or weaker made hands or become passive and do your best to see a cheap showdown which you will be even often getting for free if you opp doesn't hit or hit a weak hand.
Against MP2 you get an advantage of initiative and apply pressure on safe boards.