Keeping track of which cards have been discarded and which are still in play is a basic tactic. This aids in determining which cards to keep or discard fromrummy 9 your own hand in addition to helping you determine what cards your opponents might be holding. It might be wise to refrain from keeping similar high-value cards yourself, for instance, if you observe that a number of them have already been thrown away. Keeping your hand composition flexible is another tactic.