Chanta
Chanta 「全帯」 is the common name to honchantaiyaochuu 「混全帯么九」. It is a terminal and honor based yaku. For this yaku, every tile group and the pair must contain at least one terminal or honor tile. The hand must contain at least one honor and one non-terminal tile, otherwise the hand will score junchan, honroutou, or chinroutou instead. Occasionally, it can be referred to as chantaiyao 「全帯么」 or chantaiyaochuu 「全帯么九」.
| 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. So combinations of tile groups involving 1-2-3, 7-8-9, 1-1-1, 9-9-9, and/or any honor pairs/triplet qualify for chanta.
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's pattern 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.
Chanta is incompatible with tanyao and ittsu because both of those require a group which is not a terminal or honour -- in tanyao's case, it is required of all tiles in the hand, and for ittsu, a 4-5-6 sequence is needed.
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 (45, 56).
2. Cannot use ryanmen waits
A "ryanmen" is two consecutive tiles waiting to complete either side of a sequence, such as {34}, {45}, {78}. Terminals can never be part of a ryanmen shape - {12} and {89} are not ryanmen. A ryanmen has twice the acceptance as any other type of basic wait.
Chanta can technically can use ryanmen, via {23} and {78}. 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, 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.
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.
- 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