What kinds of melds they are trying to form can be inferred from their draws and discards. For instance, it can be a sign that an opponent is almost finished with a particular meld if they routinely draw cards from the diindiluck - casino,slots,crash,aviatorscard pile instead of the main pile. Your personal choices about which cards to keep or discard can be influenced by this information. Also, during a game, observing an opponent's body language and facial expressions can provide hints about their emotional state and degree of confidence. When discarding a card, an opponent may be struggling with their hand or worried about what you might pick up next if they appear hesitant or frustrated.