William James, The Principles of Psychology, Volume 2…
“ Ask him how, in some complex trick, he performed a certain act, why he pushed or pulled at a certain instant, and he will tell you he does not know; he did it by instinct; or rather his nerves and muscles did it of themselves.... Here is the distinguishing feature of the good player: the good player, confident in his training and his practice, in the critical game trusts entirely to his impulse, and does not think out every move. The poor player, unable to trust his impulsive actions, is compelled to think carefully all the time. ”
