1
edit
Kokushi musou: Difference between revisions
Jump to navigation
Jump to search
no edit summary
mNo edit summary |
No edit summary |
||
| Line 11: | Line 11: | ||
* [http://tenhou.net/0/?log=2014020614gm-0009-7447-66a016d0&tw=0&ts=5 Kokushi 13] | * [http://tenhou.net/0/?log=2014020614gm-0009-7447-66a016d0&tw=0&ts=5 Kokushi 13] | ||
}} | }} | ||
'''Kokushi musou''' {{kana|国士無双}}, '''kokushi''' for short, or ''' | '''Kokushi musou''' {{kana|国士無双}}, '''kokushi''' for short, or '''thirteen orphans''' in English, is one of the standard [[yakuman]] hands. It is one of the two exceptions of the "[[Mentsu|four tile groups and one pair]]" requirement for winning hands, the other being [[chiitoitsu]]. Kokushi requires having 13 unique [[terminal]]/[[honor]] tiles, and a duplicate of any of any one of these tiles. | ||
==Composition== | ==Composition== | ||
| Line 35: | Line 35: | ||
==Development== | ==Development== | ||
Kokushi is one of the three '''yakuman gosanke''' {{kana|役満御三家}}, or "the three big families of yakuman", along with [[suuankou]] and [[daisangen]]. These are the three most common yakuman, | Kokushi is one of the three '''yakuman gosanke''' {{kana|役満御三家}}, or "the three big families of yakuman", along with [[suuankou]] and [[daisangen]]. These are the three most common yakuman, though still quite rare compared to regular yaku. Kokushi is the most common yakuman in [[sanma|3-player]], but in 4-player, it is overtaken by suuankou. | ||
Restricted as closed only, this hand must draw at least 12 of the 13 required tile types. If a pair exists within the hand upon [[tenpai]], then naturally, the hand is waiting on the last remaining tile type not yet in the hand. This hand will become [[karaten|impossible]] if all four of any of the tile types are no longer available. | Restricted as closed only, this hand must draw at least 12 of the 13 required tile types. If a pair exists within the hand upon [[tenpai]], then naturally, the hand is waiting on the last remaining tile type not yet in the hand. This hand will become [[karaten|impossible]] if all four of any of the tile types are no longer available. | ||
| Line 67: | Line 67: | ||
|} | |} | ||
Any player attempting kokushi musou makes the decision at the [[haipai|beginning]] of the hand. This will depend on a couple of conditions, the most important being the number | Any player attempting kokushi musou makes the decision at the [[haipai|beginning]] of the hand. This will depend on a couple of conditions, the most important being the number of unique yaochuhai at the start. The point standing and the current [[kyoku|round]] also matter. Sometimes, players need a yakuman in order to win or [[Gyakuten|improve placement]]. | ||
* At 9 or less unique yaochuhai, the chance of | * At 9 or less unique yaochuhai, the chance of even reaching tenpai is quite low. Though the yakuman may be tempting, the expected value from attempting kokushi is lower than for a regular hand. Unless you really need a big hand, you should invoke a draw via [[Tochuu_ryuukyoku#Kyuushu_kyuuhai|kyuushu kyuuhai]] if able. | ||
* At 10 unique yaochuhai, it becomes more reasonable to go for the yakuman. | * At 10 unique yaochuhai, it becomes more reasonable to go for the yakuman. Once you have a pair, the hand's [[ukeire]] is somewhat lower than a 2-shanten [[chiitoitsu]]. That is decent when you consider the value of a yakuman hand. If you need a quick hand though (e.g. to improve placement when close to [[oorasu|all last]]), invoking a draw may still be reasonable. | ||
* At 11 unique yaochuhai, the hand is | * At 11 unique yaochuhai, the hand is close to or already at [[iishanten]], so you should usually go for kokushi. | ||
Starting with a yaochuhai pair has little effect on success for 9 or 10 yaochuhai starts, only increasing the chance of reaching kokushi by a fraction of a percentage point. However, it substantially increases the chance of winning with a non-kokushi hand, mainly because of the chance for yakuhai. | |||
If you are far ahead in the lead, then going for kokushi at 9 yaochuhai (or even less) can be considered. If it happens to succeed, you can possibly bankrupt a player and end the game. If it doesn't, then the tiles used to build kokushi are generally great for defense. | |||
=== 13-way wait development === | === 13-way wait development === | ||