Oya

The oya 「親」 (lit. parent), known in English as the dealer, is the player in the East seat. The dealer gets special benefits when winning a hand.

Dealer rotation

During the course of the game, the dealer seat rotates among the four players. Seats rotate when:

1. A player other than the dealer wins a hand.
2. The dealer fails to attain tenpai at ryuukyoku (exhaustive draw).

Once every player gets to be a dealer once, the round wind changes. In a hanchan, everyone gets 2 chances at the dealer seat.

Conversely, if the dealer wins a hand, or is in tenpai at exhaustive draw, then the seats do not rotate. Each time this happens, the game length is extended by 1 extra hand.

Useful Info

When a player is the dealer, the following properties apply:

• The dealer draws first, which is a slight advantage to hand speed.
• The dealer's hand value is worth 50% more (or about 50% more) than non-dealer's.
• If the dealer wins the hand, or is tenpai at exhaustive draw, the wind seating does not rotate, thus extending the game by an extra hand (renchan).
• The dealer pays x2 as much when another player wins via tsumo. (Dealers do not pay more when dealing in.)

Due to the +50% point modifier, players greatly benefit from being the dealer. Games are often decided by dealer turns. A lucky player may rise from 4th all the way to 1st through consecutive renchans.

However, being the dealer is not always helpful:

• When a dealer has a large lead near the end of the game, they should avoid winning to avoid extending the game. After all, each renchan gives the other players a chance to build a yakuman and comeback.
• When another player wins by tsumo, the dealer has to pay more. The extra points lost from tsumo can be significant during close games or with big hands.

The current dealer is denoted by using the dealer marker. Alternatively, the dealer marker notes the original dealer, and some other method is used to mark the current dealer.

Rule variations

Renchan

There are two main rule variations regarding the dealer's renchan:

Renchan conditions:

• Agari renchan: The dealer only renchans after a win.
• Tenpai renchan: The dealer renchans after a win, or if tenpai at exhaustive draw.

Agariyame: In the last round, dealers may or may not be allowed to decline a renchan.

• Some rules let the last dealer choose to end the game when they win the hand.
• Other rules end the game when a 1st-place dealer wins, regardless of whenever they want to or not.
• Other rules do not let the dealer to end the game. The game ends when the dealer does not win.

Tiebreakers

When players are tied at the end of the game, some rulesets break the tie based on initial dealership. In order of priority, 1st dealer (East player in East 1) > 2nd dealer (South player in East 1) > 3rd dealer (West player in East 1) > 4th dealer (North player in East 1). This order is used because, traditionally, being the last dealer is seen as an advantage. The last dealer can end the game as soon as they reach first place in the last round; other players do not have this luxury.