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Eternal Life
Path: LifeAndDeath   · Prev: DoorGroup   · Next: ApproachingALifeAndDeathProblemTheRightWay
Path: SecondCourseOnKo   · Prev: BentFourInTheCornerIsDead   · Next: RepeatingPositions

    Keywords: Ko, Rules

Chinese: 长生
Japanese: Chosei

Eternal life is yet another situation where a void game (no result: neither player wins, but neither player loses) can occur, under rulesets which permit such a thing. Several special rules, such as superko and the Ing Ko Rule, forbid the recurring sequence to occur.

However, eternal life is so rare in games that if one occurs, a Chinese Go text says that:

  You should buy fish, vegetables, meat and wine
  And have a good party to celebrate yourself

Of course, it's an exaggeration...

Example

[Diagram]
Eternal life

This is the situation to begin with.


[Diagram]
Eternal life

B1 begins by sacrificing two stones (to prevent the formation of bulky five)...


[Diagram]
Eternal life

B3 takes back two white stones...


[Diagram]
Eternal life

White makes a throw in at W4 to destroy the eye, and the cycle repeats itself when B5 sacrifices two stones again.



White has the option of making seki:

[Diagram]
Seki



Q: But suppose White needs to kill Black in order to win, and Black would never let go of his group, then eternal life occurs.

A: Strictly speaking the position after White 1 in the Seki diagram is not seki, but a hyperactive position. However, when it is correct to make the play, it will almost always become seki.


There was some excitement about this thirty years ago when a variation of the kado joseki played in a title game Sakata - Yamabe could have led to chosei.


SL material

Kanazawa Attempts 85

External references

[ext] http://www-2.cs.cmu.edu/~wjh/go/rules/Japanese.html


Authors



Path: LifeAndDeath   · Prev: DoorGroup   · Next: ApproachingALifeAndDeathProblemTheRightWay
Path: SecondCourseOnKo   · Prev: BentFourInTheCornerIsDead   · Next: RepeatingPositions

This is a copy of the living page "Eternal Life" at Sensei's Library.
(OC) 2003 the Authors, published under the OpenContent License V1.0.