According an article in The Examiner, one shouldn't look at a player's face for clues whether they have a good/bad hand. That's right! New research suggests an experienced poker player's face won't reveal any signs of a good or a band hand, however, there are still other clues in the body language.
Researches have found that arm movements of experienced poker players were more predictable of good/bad cards than clues revealed by the face. Apparently there's a difference in when players moved their arms to move chips forward to make a bet. The ones holding good cards had more smoother arm movements while the ones with bad cards had awkward arm movements.