Also, knowing which cards your opponents are discarding or picking up can give you important information about their tactics. An opponent may be getting close to forming a msattachateld with cards if they routinely remove cards from the discard pile. You can modify your own play by monitoring these trends, possibly by eliminating cards that would aid them in finishing their runs or sets. Although it takes time & focus to become proficient at card counting, it can significantly alter the outcome of competitive situations.