Chanta
Chanta 「全帯」, short for honchantaiyaochuu 「混全帯么九」, is scored when every tile group and the pair contains at least one terminal / honor tile. The hand must contain at least one honor and one non-terminal tile to score chanta, or it would score the more valuable junchan or honroutou instead. This yaku can also be called chantaiyaochuu 「全帯么九」 or chantaiyao 「全帯么」.
| Type | Yaku |
|---|---|
| Kanji | 混全帯么九 |
| English | Terminal or honor in each group |
| Value |
2 han (closed) 1 han (open) |
| Speed | Medium |
| Difficulty | Medium |
Tile pattern
Waiting for: 
Note: This hand is also waiting for 
, but it would not be chanta.
Formation
By definition, every tile group must include a terminal or honor tile. Therefore, the only tile groups allowed are 1-2-3, 7-8-9, 1-1-1, 9-9-9, and honor triplets. In addition, you must have a terminal/honor pair.
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 | |
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Chanta is incompatible with tanyao (which requires no terminal/honors) and ittsu (which requires a 4-5-6 sequence). Chanta is similar to junchan; however, the two can never combine as junchan implies a chanta hand. Honroutou likewise implies chanta and is thus incompatible. Chanta with toitoi or chiitoitsu actually forms honroutou instead of chanta, while chanta with chinitsu is actually junchan instead of chanta.
Development
While chanta can be seen as the converse of tanyao, chanta is much slower. This yaku is rarely seen in riichi mahjong, due to a few reasons:
1. Smaller tile acceptance
Middle tiles are more efficient than terminals/honors for hand development. This can be measured by tile acceptance - the more tiles that can be used to form a sequence/pair/triplet, the higher the tile acceptance, and the more efficient the tile (generally) is.
- A lone honor tile can only be used in a pair/triplet. Therefore, a lone honor only accepts itself.
- A lone 1 accepts 1, 2, or 3. There is no way to get a ryanmen wait off with a lone 1.
- A lone 5 accepts 3, 4, 5, 6, or 7. There are two ways to get a ryanmen wait (4-5, 5-6).
Chanta is often stuck with 1's, 9's, and honors, which usually means less efficiency.
2. Cannot use ryanmen waits effectively
A "ryanmen" is two consecutive tiles waiting to complete either side of a sequence, such as 3-4, 4-5, 7-8. Terminals can never be part of a ryanmen shape, as 1-2 and 8-9 are not ryanmen. A ryanmen has twice the acceptance as any other type of basic wait.
Chanta can technically can use ryanmen 2-3 and 7-8. However, it is only half as effective, as you only get chanta with 1/2 of the winning tiles (1 and 9, respectively). Therefore, since chanta cannot use ryanmen at its full potential, it is slower to develop than a regular hand. Plus, in order to guarantee chanta in tenpai, your hand must have a bad wait (<= 4 tiles left in the wall).
3. Not valuable
Since chanta is so slow, and only worth 2 han (even less when opened), it usually isn't worth the effort. Even without considering riichi, there are easier ways to get 2 han, such as tanyao + pinfu, pinfu + 1 dora, pinfu + iipeikou, and so on. Therefore, players will rarely go for chanta. Chanta is even less common when red fives are used, since tanyao + 1 aka dora is already worth as much as chanta.
When to go for chanta
Chanta can be good to aim for when:
- You need a quick hand, and chanta/junchan is your only realistic way your hand can complete open.
- Chanta/junchan is the fastest way to complete your hand at all (e.g. hand with many penchans and terminal/honor pairs)
- You happen to get most of the required tiles already (e.g. 123 sanshoku with other terminals/honors mixed in).
- You were going for kokushi musou, but kokushi became impossible early in the round, and you are desperate to win.
External links
- Chanta in Japanese Wikipedia