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

VisualWikitext

Latest revision as of 11:23, 25 August 2024

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.

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

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]] 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. Any [[naki|open call]] ruins the yaku, even if the pattern already existed within the hand. If this pattern is found twice in one hand, an alternative yaku, [[ryanpeikou]], is scored.
+'''Iipeikou''' {{kana|一盃口}} is a [[yaku]] scored when a hand has two identical [[sequence]]s (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]].
 ==Tile pattern==
@@ Line 21: / Line 21: @@
 ==Formation==
-This yaku usually appears 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.
+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. If you make any open call (chii/pon/open kan), iipeikou can never be scored, even if the call was unrelated to the identical sequences. However, the ''sequences'' do not have to be closed: if you declare [[ron]] with a closed hand, iipeikou can still be scored, even if the winning tile completed the 2nd identical sequence.
+Note that iipeikou requires the hand to be closed, so any [[naki|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 ===
+== Compatibility ==
 {{main|Yaku compatibility}}