Iipeikou
Iipeikou 「一盃口」 is a yaku scored when a hand has two identical sequences (two sequences with the same number and suit). It also requires the hand to be closed. If a hand has "two iipeikou"s, it instead scores ryanpeikou.
| Type | Yaku |
|---|---|
| Kanji | 一盃口 |
| English |
Identical sequences Double sequences |
| Value | 1 han (closed only) |
| Speed | Medium |
| Difficulty | Easy |
Tile pattern
Rearrangement
Arrangement of tiles is irrelevant, as long as two groups of tiles form the identical sequences.
Formation
When the tiles are sorted, iipeikou may appear as three groups of consecutive pairs. However, since they must be interpreted as two sequences to score as iipeikou, a hand can never score both iipeikou and chiitoitsu.
Note that iipeikou requires the hand to be closed, so any open call (chii/pon/open kan) will invalidate this yaku, even if the call was unrelated to this yaku. However, it is allowed to call ron and score this yaku, even if the winning tile was the one to complete the iipeikou pattern.
Compatibility
^ Ippatsu requires riichi to be of any use.
| RCH | DRI | IPP | SMO | TAN | PFU | IPK | ITT | YAK | SDJ | SDO | TOI | SNA | SNK | CHA | JUN | RPK | SSG | HRO | HON | CHN | CHI | RIN | HAI | HOU | CHK | |
| IPK |  |
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Iipeikou requires two sequences, and as a result is incompatible with sanshoku doukou, toitoi, honroutou, chiitoitsu, sanankou, and sankantsu, all of which require either at least three koutsu/kantsu or a seven pair structure. The final incompatibility is with ryanpeikou, as ryanpeikou implies iipeikou and so iipeikou is not counted.
Iipeikou is often combined with pinfu, which also requires sequences. Iipeikou can naturally be obtained with shapes like 4456 and 4556, which a pinfu hand may have due to tile efficiency reasons.
External links
- Iipeikou in Japanese Wikipedia