This is because they are more likely to be discarded if an opponent declares Rummy. Players should also think carefully about when to discard. When opponentrummy towns have had more time to form their hands, discarding later in the game may have more weight than discarding early. Players must monitor which cards have been discarded and which are still in play as the game goes on. Making decisions about what to keep and what to let go of can be influenced by this knowledge.
