Rummy players need to build a well-rounded strategy that includes both offensive & defensive play if they want to succeed. Focusing on forming melds as fast as you can while keepteen+patti+golding your hand flexible is an effective offensive tactic. This entails being willing to modify your plan of action in response to the cards you draw and the moves your opponents make. For example, it might be prudent to keep cards that could help you form a meld if you observe that your opponent is discarding them rather than throwing them away yourself.
