East Round

East Round

East Round (東場, とんば) is the first round of a standard hanchan (full game) in riichi mahjong, where the prevailing round wind is East. Each of the four players takes at least one turn as dealer during this round, resulting in a minimum of four hands played.

Detailed Explanation

Structure

A hanchan consists of two rounds:

1. East Round (Tonba): Round wind is East
2. South Round (Nanba): Round wind is South

Each round guarantees that all four players serve as dealer at least once. Since the dealer rotates clockwise and can repeat dealership by winning or drawing in tenpai, an East Round typically lasts 4-8 hands depending on dealer wins.

Round Wind Significance

During East Round, the round wind is East. This affects scoring in two ways:

Yakuhai Value: Players holding triplets of East wind tiles earn yakuhai (1 han) because East matches the round wind, regardless of their seat wind. For the player seated as East, a triplet of East tiles provides 2 han (round wind + seat wind).

Dealer Advantage: The starting dealer (seated East) in the East Round has a scoring advantage—dealer wins pay 1.5× the normal amount. If the dealer wins repeatedly, they can accumulate significant point leads before other players get their dealer turns.

Round Progression

Dealer Rotation: After each hand, if the dealer doesn’t win (and isn’t in tenpai during a draw), dealership passes clockwise. The round continues until all four players have served as dealer at least once.

Transition to South Round: Once all four players have been dealer and the current dealer fails to win or draw in tenpai, the game transitions to South Round. The same rotation system continues with South as the prevailing wind.

Tonpuu Rule (East-only games): Some shorter game formats play only the East Round, ending after four hands (or when dealer rotations complete). These are called “tonpuu” games and last about half as long as full hanchans.

Usage Example

The game begins in East Round with Player 1 as the initial dealer (seat wind East, round wind East). Player 1 wins their first hand with a triplet of East tiles, scoring 2 han from yakuhai (seat wind + round wind). Because they won, Player 1 retains dealership for the next hand (renchan). After Player 1 finally loses a hand, dealership rotates to Player 2. The East Round continues until all players have been dealer at least once, then transitions to South Round.

Related Terms

South Round: The second round of a hanchan where the round wind is South. Follows the East Round.

Hanchan: A full game consisting of East Round and South Round. Typically 8-12 hands total.

Dealer: The player serving as dealer (Oya). Scores 1.5× normal payments and can repeat dealership by winning.

Round Wind: The prevailing wind for the current round. Affects yakuhai scoring for wind triplets.

Tonpuu: An abbreviated game format consisting of only the East Round (four hands minimum).