just a thought about the Korchnoi Petrosian game fragment. In your notes you say that Korchnoi must have spotted the final move (Kb5) at the start when he moved the pawn. I'm thinking that he probably knew the position in the fen below was won, it looks like the kind of position that one heads to knowing it's won.
If someone asked me about this I'd have said it's a draw, so it's handy to know that there's a zugzwang trick and that whoever has the move wins. Thanks for bringing it to my attention, once again I enjoyed the blog so thankyou for that too.