You can learn a lot about the melds they are attempting to form by paying close attention to the cards they draw & discard. If an opponent routinely takes cards from treferral code of sbihe discard pile instead of the stockpile, for example, it can mean that they are almost done with a meld using those particular cards. You can use this information to help you decide which cards to keep and which to discard. Also, you can tell how confident your opponents are with their hands by observing the timing of their moves.