take notes on stuff that stands out, obv.

I think spots where he defines what his range might be in what could be a polarized spot is interesting:

1. If he shows up light in a 3-bet pot especially a squeeze spot.
2. What kind of hand he has when he donks the flop.
3. What he check-raises flop with.
4. Does he play his draws fast?
5. If he shows up in a spot where he flatted AA/KK/AK pre.

etc.