Someone told me something astonishing two days ago:
I used to be playing a clairvoyant, where my job was to guess what card the person sitting in front of me holds, without looking at this card. I got quite good at this, my answers were usually correct. Of course, there was nothing supernatural here: all it took was to observe my opponent carefully. Mimics, microgestures, where does this person look at any given moment are everything. The amount of information people are telegraphing this way is astonishing.
I tried my luck in poker and once again careful observation of my opponents proved to be my most important skill. Indeed, I soon stopped looking at my hand at all! This was not only out of arrogance: if I did not know my hand I knew I could not telegraph it to other players the same way they were telegraphing theirs to me. On the other hand, I knew perfectly well whose hand was good, whose hand was bad, who was bluffing and who was not - and this was enough for me to play well.
I admit, though, that I was only playing against amateurs; I suppose professional poker players actually do keep their pokerfaces and I wouldn't be able to gain that much information just by observing them!
Wow. Just wow. Of course I knew non-verbal communication existed, but this...?
How to avoid giving subconsciously that much information to other players? How do proffessional poker players avoid this?