I will assume, that this is the case.
I'm struggling slightly to understand the action as you say stacks are 100bb which is $200. But then you put $50 in preflop and in the flop, $100 turn and still have $115 left. So $315 in total or 157.5bb - I am assuming this.
So am I. However the first thing to notice, is, that when Villain open to $15, then its more like, the effective stack is somewhere around 60BB, if we compare to online games or high stakes live games, where more normal sizing is used. And this matter, because right off the bat we are typically very happy to stack off AA for 60BB in a 3-bet pot. It will generally need to be like the worst possible runout for us to consider not stacking off.
Preflop
A $15 open is ridiculous from BU, but maybe this is a live game where it is more normal. I would typically 3bet more like 4x to $60 but it would be stack size dependent. Anyway I think it's fine to go $50.
I agree with this. We can make it a bit larger here and not give the opponent such a good price to take position on us.
Flop
Great flop, villain could have 66 or 44 but so many other hands you are crushing. There is also the possibility he has A4s (and you dont block either combo). Check (looking to check raise) or cbet are fine and half pot seems fine on such a good flop.
I would prefer a slightly smaller sizing here, because its such a way ahead / way behind spot. If we have a hand like TT or JJ, we dont mind some protection from random overcards. But with AA we want him to stay involved with hands like AQ, AJ, KQ and so on and so forth, because those hands are basically drawing dead now.
Turn
You lose to 75 now and 33, but these are a small part of his range. He will have plenty of overpairs that will continue to call or bet if checked to. Again check or bet fine but I dont like your size. Generally we should be betting big on turn (like you did) but stack sizes are awkward. It looks like pot is 150 and you have 215 behind. Betting 100 makes you pretty much pot committed with only a 33% bet left. So you should either go smaller (e.g. 75, to leave 140 left into a pot if 300 on river) or just shove it all. I also quite like a check as we can then check raise all-in and if it checks back we can shove river and look bluffy, hopefully getting called lighter.
River
With so little behind you are never check folding, so shoving is the play to hope to get called by worse, if he has you beat so be it.
I agree. If Hero ended up losing to something, which connected with this low board, then the main thing to look at is the preflop 3-bet sizing. A larger sizing can make some hands with cute little cards go away, and thats fine. Or if they still continue, then at least we charge them more and reduce their implied
odds.