Toitoihou: Difference between revisions

Toitoihou
Type	Yaku
Kanji	対々和; 対々
English	All triplets
Value	2 han
Speed	Medium
Difficulty	Easy

VisualWikitext

Revision as of 12:42, 24 August 2024

Toitoihou 「対々和」, often shortened to toitoi 「対々」, is a yaku scored when all four tile groups are triplets (and/or kans), giving it the English name of "All Triplets".

Tile pattern

Agari:

or

Agari:

or

Closed toitoi

Ron:

or

If this hand wins by tsumo, then it counts for the suuankou yakuman. Otherwise, it's a toitoi mixed with sanankou.

Formation

As the name implies, this yaku requires koutsu. Usually, this yaku is called open due to the ability for pon to claim discarded tiles from any player, giving this yaku the nickname of "pon palace". This yaku does not reduce in value once opened.

Viability

Naturally, this yaku is reasonable to go for with many triplets and/or pairs. However, toitoi often looks easier than it actually is. There are only 2 tiles that can convert a pair into a triplet (4 tiles in the game, -2 already in hand = 2 tiles left); there are 8 tiles that can convert a ryanmen into a sequence. While pon can turn pairs into triplets, the tiles needed to pon may not be discarded. The 2 tiles could be in the dead wall, or used in an opponent's hand.

Pairs made out of middle tiles (tiles from 3-7) are particularly hard to pon, because middle tiles are generally more likely to be kept in an opponent's hand. When there are multiple pairs made out of middle tiles, this yaku becomes slower to complete. In addition, a hand with many pairs can also form chiitoitsu.

Some (rough) rules of thumb between toitoi and chitoitsu are:

With 4 pairs and one turns into a sequence or triplet, it is often best to go for the regular hand structure. This may or may not be toitoi. Exception: if the hand is entirely disconnected except for the single sequence/group, then go chiitoitsu.
With 5 pairs, chiitoitsu is preferred. Keeping the option for toitoi is fine (e.g. 4 pairs, 1 triplet, 2 lone tiles. The hand can turn into chiitoi if you discard the triplet, can toitoi if you pon) so long as the pairs are reasonable to pon.
With 4-5 pairs, and one of the pairs cannot be turned into a triplet, because both remaining tiles of the pair are visible, then favor chiitoitsu.

Compatibility

Main article: Yaku 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
TOI

Toitoi is incompatible with any yaku requiring a sequence, meaning pinfu, iipeikou, ittsu, sanshoku doujun, ryanpeikou, and chankan (since it can only win on a sequence wait). It also cannot be combined with chiitoitsu, since it doesn't use mentsu.

Toitoi with mentsumo and junchan actually form yakuman, as suuankou and chinroutou respectively. Toitoi with chanta forms honroutou instead.

External links

対々

Toitoihou in Japanese Wikipedia

@@ Line 25: / Line 25: @@
 === Viability ===
-Naturally, this yaku is reasonable to go for with many triplets and/or pairs. However, toitoi often looks easier than it actually is. There are only 2 tiles that can convert a pair into a triplet (4 tiles in the game, -2 already in hand = 2 tiles left); there are 8 tiles that can convert a [[ryanmen]] into a sequence. While you can pon to turn pairs into triplets, your opponents might not discard the tiles you need to pon. The 2 tiles could be in the [[dead wall]], or used in an opponent's hand.
+Naturally, this yaku is reasonable to go for with many triplets and/or pairs. However, toitoi often looks easier than it actually is. There are only 2 tiles that can convert a pair into a triplet (4 tiles in the game, -2 already in hand = 2 tiles left); there are 8 tiles that can convert a [[ryanmen]] into a sequence. While pon can turn pairs into triplets, the tiles needed to pon may not be discarded. The 2 tiles could be in the [[dead wall]], or used in an opponent's hand.
-Pairs made out of middle tiles (tiles from 3-7) are particularly hard to pon, because middle tiles are generally more likely to be kept in an opponent's hand. If you have multiple pairs made out of middle tiles, this yaku becomes slower to complete. In addition, a hand with many pairs can also form [[chiitoitsu]].
+Pairs made out of middle tiles (tiles from 3-7) are particularly hard to pon, because middle tiles are generally more likely to be kept in an opponent's hand. When there are multiple pairs made out of middle tiles, this yaku becomes slower to complete. In addition, a hand with many pairs can also form [[chiitoitsu]].
-Some (very rough) rules of thumb between toitoi and chitoitsu are:
+Some (rough) rules of thumb between toitoi and chitoitsu are:
-*If you have 4 pairs and one turns into a sequence or triplet, you should probably go for a regular hand structure. This may or may not be toitoi.
+*With 4 pairs and one turns into a sequence or triplet, it is often best to go for the regular hand structure. This may or may not be toitoi. Exception: if the hand is entirely disconnected except for the single sequence/group, then go chiitoitsu.
-*If you have 5 pairs, you should likely go for chiitoitsu. Keeping the option for toitoi is fine (e.g. 4 pairs, 1 triplet, 2 lone tiles. The hand can turn into chiitoi if you discard the triplet, can toitoi if you pon) so long as the pairs are reasonable to pon.
+*With 5 pairs, chiitoitsu is preferred. Keeping the option for toitoi is fine (e.g. 4 pairs, 1 triplet, 2 lone tiles. The hand can turn into chiitoi if you discard the triplet, can toitoi if you pon) so long as the pairs are reasonable to pon.
-*If you have 4-5 pairs, and one of the pairs cannot be turned into a triplet, because both remaining tiles of the pair are [[Kabe#Visible TIles|visible]], then favor chiitoitsu.
+*With 4-5 pairs, and one of the pairs cannot be turned into a triplet, because both remaining tiles of the pair are [[Kabe#Visible TIles|visible]], then favor chiitoitsu.
 == Compatibility ==