Keeping cards that can be used in both sets and runs, for example, can give you options as the game goes on. For instance, you could aim for a rdiamond slots 777un of nines if you have two nines and a ten of hearts. You could also watch for another ten or an eight of hearts to form at the same time. This flexibility can be extremely important in Rummy, as the game's dynamics can change quickly depending on the cards that are drawn and discarded.
