Chuuren poutou
Chuuren poutou 「九連宝燈」 is a yakuman scored when a hand contains the 13-tile pattern of: 1-1-1-2-3-4-5-6-7-8-9-9-9 of the same suit, plus any one tile from the same suit. In addition, the hand must be closed. Calling a kan on the 1 or 9 invalidates the yakuman.
| Type | Yakuman |
|---|---|
| Kanji |
九連宝燈 純正九蓮宝燈 |
| English |
Nine gates Pure nine gates |
| Value | Yakuman (closed only) |
| Speed | Very slow |
| Difficulty | Very hard |
A special pattern of chuuren tenpai, junsei chuuren poutou 「純正九蓮宝燈」 ("pure churren poutou"), results in a 9-sided wait. It occurs when you complete the 1-1-1-2-3-4-5-6-7-8-9-9-9 pattern at tenpai, without any duplicate tiles. Unlike the 13-sided kokushi musou, this 9-sided wait is formed naturally with the four sets and a pair. Some rule variations consider this a double yakuman.
Tile pattern
Regular
Waiting for: 
Yasume:
If this hand wins with either of the yasume tiles, the hand will score only chinitsu rather than the yakuman.
Nine tile wait
- Waiting for:
In the above animation, the different winning tiles show the shifting tile group configurations as they count up 1 through 9. The groupings change with each winning tile. Sequential groups are marked in green, while the indicated pairs are marked blue. Then in red, the 1 or 9 indicated as triplets.
Value
Chuuren is a yakuman hand. However, while tenpai, some tile waits may actually award the hand for a considerably less value of haneman, as a closed chinitsu. Some rules award a double yakuman instead when the hand goes out from the 9-sided wait.
Development
Since this hand is made up of one suit, it overlaps with chinitsu during development. In fact, many tenpai formations may result in chinitsu instead of the yakuman.
The key to this yakuman is the possession of ankou of both 1's and 9's of one suit. If two copies of either 1 or 9 are unavailable, then the yakuman becomes impossible. Similarly, if all four of any other numbered tile is unavailable, then it also becomes impossible. Of course, gathering a string of 2-8 is also difficult.
External links
- Chuuren poutou in Japanese Wikipedia
- Mathematical study
- Chuuren (YouTube)
- Kojima Takeo