You can determine the possible composition of their hand by observing which cards they decide to keep and which ones they discard. When making your own moves, this knowledge can help you makerummy great better decisions about which cards to keep and which to discard. Also, reading your opponents' responses and body language can reveal information about their tactics & degree of confidence. Anxious or hesitant players might be having trouble with their hand, but confident players might be on the verge of winning. Recognizing these subtle clues will help you modify your gameplay.