Nagashi mangan 「流し満貫」 is a special yaku. It operates just like ryuukyoku but the point exchange is larger. As the name implies, the amount of mangan is exchanged. Unlike all other possible hands, this yaku emphasizes the discards, rather than the hand itself. As for the dealer rotation, only the dealer's hand matters in relation to tenpai. Even if the dealer loses points due to nagashi mangan, the seating may be retained if the hand is in tenpai. That is assuming the rule of tenpai-renchan, as opposed to agari-renchan.
Scoring nagashi mangan
This yaku has specific conditions for qualification:
- The hand must play all the way to ryuukyoku, which means no one must win a hand before all the tiles are drawn.
- Every discard of the player must be a terminal or an honor tile.
- The player may not have called any tiles.
- No tiles may have been called from the player's own discard pile.
- Upon reaching ryuukyoku, the player does not need a hand in tenpai. If the dealer is in tenpai, then the wind seating does not rotate; but it does otherwise.
As the name implies, successful execution of nagashi mangan rewards the player in the amount of a mangan tsumo. If multiple players win with nagashi mangan, the different tsumo payments occur independently of each other. For instance, if East and South complete nagashi mangan, then their payments to each other will cancel out, and North and West will each pay 4000 to East and 2000 to South.
Timing at ryuukyoku
When the wall is empty and the last discard has not been called for a win, special rulesets may differ on the exact procedure to score nagashi mangan per house rules.
- Some rules score nagashi mangan like a win, before players reveal tenpai hands. Honba increase the payment, and the winner collects any riichi sticks on the table. The noten penalty is cancelled and noten riichis are not punished with chombo. Hand progression depends on whether East has won with nagashi mangan.
- Some rules merely score nagashi mangan like a bonus payment, not as a win. Nagashi mangan happens at the same time as players reveal tenpai hands. The noten penalty is cancelled and replaced by the nagashi mangan payment, but that payment is not affected by honba or riichi sticks. Chombo takes precedence over nagashi mangan payments. If there is no chombo, then hand progression depends on whether East is tenpai.
In the extremely rare event when more than one player is awarded nagashi mangan simultaneously, then each player receives the equivalent of a mangan tsumo. That implies even a winning player pays into the tsumo payment.
- Nagashi mangan in Japanese Wikipedia