When your opponent discards a card that you need for a meld, for instance, picking it up not only benefits you but also prevents your opponent from finishing their own mslots meta win apkelds. The discard pile is also a psychological tool that players can employ. By discarding specific cards, you can give your opponents clues about the melds you are attempting to make or avoid. For example, early discarding of a high-point card could give opponents the impression that you are not interested in creating high-value sets.