On RHP: I am not sure what is my best move but finally press "submit move" and go out for a walk. After about 30 minutes not really thinking about chess, I have a flash of the position clearly in my mind and realise I have not made the best possible move.
From my own experiences In the world outside of chess I know that after a while certain skills which require considerable concentration and judgement to begin with can in fact become almost routine. So I am thinking that after a while, good experienced players can almost play a game by "the seat of their pants" - they only have to concentrate when they come across something a little different from a good player. I know when I was at school a visiting chess master took on about 20 of us at the same time and most of the time he just took a glance at each board before making a move and I think he won all of the games - (I can't remember exactly it was a long time ago).
Maybe I have not put this very clearly but it seems there is a connection between, experience, visualisation and just gut feeling. I get the feeling that some players hardly have to think before making a move they just know.
I would be interested to read what the 'regulars' on this forum have to say.