To speed up the game, a player holding a probable winner is encouraged to show the hand without delay. If there is a side pot, players involved in the side pot should show their hands before anyone who is all-in for only the main pot. Robert's Rules of Poker state that the last player to take aggressive action by a bet or raise is the first to show the hand-unless everyone checks (or is all-in) on the last round of betting, then the first player to the left of the dealer button is the first to show the hand. Because exposing a losing hand gives information to an opponent, players may be reluctant to expose their hands until after their opponents have done so and will muck their losing hands without exposing them. Cards speak for themselves: the actual value of a player's hand prevails in the event a player mis-states the value of their hand.
To win any part of a pot if more than one player has a hand, a player must show all of their cards faceup on the table, whether those cards were used in the final hand played or not. In poker, the showdown is a situation when, if more than one player remains after the last betting round, remaining players expose and compare their hands to determine the winner or winners.