An opponent may not be interested in certain ranks or suits if you observe that they are routinely discarded; if this is the case, you can safely pick them up if they fit your own melding strategy. Players should also exercise caution wherummy nobelen it comes to what they throw away. If your opponent is about to go out, it may be dangerous to discard high-point cards; instead, think about discarding lower-point cards that are less likely to aid your opponents in forming melds. Also, it might be prudent to hold onto a card for a little while longer or even strategically discard it later when it becomes less relevant if it has the potential to complete an opponent's meld but does not fit into your particular strategy.