Iipeikou: Difference between revisions

Iipeikou
Type	Yaku
Kanji	一盃口
English	Identical sequences; Double sequences
Value	1 han (closed only)
Speed	Medium
Difficulty	Easy

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Revision as of 18:56, 26 March 2024

Iipeikou 「一盃口」 is a standard yaku involving two identical sequences. Identical means that both shuntsu must be of the same numbers and suit. This yaku also requires the hand to be closed. A single open call invalidates the yaku, even if the pattern exists within the hand. If this pattern is found twice in one hand, an alternative yaku, ryanpeikou, is scored.

Tile pattern

Rearrangement

Arrangement of tiles is irrelevant, as long as two groups of tiles form the identical sequences.

Formation

This yaku is usually presented as three groups of consecutive pairs. However, the rule interpretation views them as a two sequences. Potential acquisition of this yaku is best recognizable when five out of the six tiles are present in the hand.

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
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

一盃口

Iipeikou in Japanese Wikipedia

@@ Line 8: / Line 8: @@
 |gameExample = * [http://tenhou.net/0/?log=2014011309gm-0009-7447-f766aece&tw=0&ts=4 Iipeikou] with [[damaten]]
 }}
-'''Iipeikou''' {{kana|一盃口}} is a standard [[yaku]].  Its feature composes of two identical [[mentsu#shuntsu|sequences]].  By identical, both shuntsu must be of the same number and same suit.  This patter may also be produced twice in one hand, to form an alternative yaku, [[ryanpeikou]].
+'''Iipeikou''' {{kana|一盃口}} is a standard [[yaku]] involving two identical [[mentsu#Shuntsu|sequences]].  Identical means that both [[shuntsu]] must be of the same numbers and suit.  This yaku also requires the hand to be closed.  A single [[naki|open call]] invalidates the yaku, even if the pattern exists within the hand.  If this pattern is found twice in one hand, an alternative yaku, [[ryanpeikou]], is scored.
 ==Tile pattern==
@@ Line 23: / Line 23: @@
 This yaku is usually presented as three groups of consecutive pairs.  However, the rule interpretation views them as a two [[shuntsu|sequences]].  Potential acquisition of this yaku is best recognizable when five out of the six tiles are present in the hand.
-=== Compatability ===
+=== Compatibility ===
-{{main|Yaku compatability}}
+{{main|Yaku compatibility}}
-{{yakuheader}}
+{{Yaku compatibility table|IPK}}
-| IPK || {{yes}} || {{yes}} || {{yes}} || {{yes}} || {{yes}} || {{yes}} ||bgcolor="000000"|  || {{yes}} || {{yes}} || {{yes}} || {{no}} || {{no}} || {{no}} || {{no}} || {{yes}} || {{yes}} || {{no}} || {{yes}} || {{no}} || {{yes}} || {{yes}} || {{no}} || {{yes}} || {{yes}} || {{yes}} || {{yes}}
-|}
-==Value==
+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.
-{{main|Scoring}}
-{| class="wikitable" width=40% align=right
+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.
-|-
-!rowspan=2 width=10%| Han/Fu !!colspan=2 width=40%|Ron !!rowspan=2 width=10%| Han/Fu !!colspan=2 width=40%| Tsumo
-|-
-!width=20%| Non-dealer !!width=20%| Dealer !!width=20%| Non-dealer !!width=20%| Dealer
-|-
-|colspan=3| ''Minimum possible'' ||colspan=3| ''With mentsumo''
-|-
-|align=center| '''1 - 40''' ||align=center| 1300 ||align=center| 2000 ||align=center| '''2 - 30''' ||align=center| 1000/500 ||align=center| 500
-|-
-|colspan=3| ''Maximum without other yaku'' ||colspan=3| ''With mentsumo''
-|-
-|align=center| '''1 - 80''' ||align=center| 2300 ||align=center| 3400 ||align=center| '''2 - 70''' ||align=center| 1300/2600 ||align=center| 2600
-|}
-This yaku is required to be closed only.  Even if the pattern exists within an open hand, the yaku will not be counted in this case.
-* '''Minimum''' ''(Iipeikou only)''
-: {{#mjt: 556677p13m44466s}} Agari: {{#mjt: 2m}}
-* '''Maximum''' ''(Iipeikou only, when not seated north)''
-: {{#mjt: 556677s2m}} {{#mjt:0z11s00440z}} Agari: {{#mjt: 2m}}
-The lowest possible score for a iipeikou nomi (only) hand is 1 han and 40 fu.  The 40 fu is derived from a closed ron (10 fu) plus possession of another fu generated form, either by certain [[machi|wait patterns]] or [[koutsu|triplet(s)]].  In order for the hand to involve 30 fu, it would have to involve pinfu with the closed ron.  Likewise, a win by tsumo may involve a similar form.  Given the closed only aspect of this hand, it is unavoidable to score an "iipeikou only" hand without a combination with [[mentsumo|closed tsumo]].
-The highest possible score for an iipeikou nomi (only) hand is 1 and 80 fu.  The 80 fu is derived from two groups of non-yakuhai [[jihai|honor tiles]] or [[terminal|terminals]] used for [[kan|closed kans]].  With that, the wait pattern involves a [[tanki|single tile]].  For tsumo, the difference again involves a closed tsumo and the lack of 10 fu derived from a closed ron.  Naturally, when combined with other yaku, the score can be significantly higher.
 ==External links==