Every move an opponent makes reveals information about their strategy and possible hand structure. For example, it might be a sign that an opponent is almost done with their melds if they routinely draslots machine onlinew cards from the discard pile instead of the deck. You can use this information to guide your own choices regarding which cards to keep or discard. Knowing which cards have been discarded can also help you figure out what melds your opponents are attempting to create. You can tell an opponent is aiming for a heart-based run or set if you see them discarding a number of hearts while keeping others.