There are 13 tricks in every hand of Batak, because the 52-card deck is dealt evenly among four players, giving each 13 cards. Each trick uses one card from every player, so all 13 rounds together exhaust everyone's hand. This fixed number matters for bidding, since your bid is a promise to win a certain share of those 13 tricks. Knowing exactly how many tricks exist helps you judge whether a bid is realistic and how many are still left to fight over as the hand progresses. When all 13 tricks have been played, the hand is scored and the next deal begins.