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Eternal Life
Path: LifeAndDeath · Prev: DoorGroup · Next: ApproachingALifeAndDeathProblemTheRightWay Path: SecondCourseOnKo · Prev: BentFourInTheCornerIsDead · Next: RepeatingPositions
Keywords: Ko, Rules
Chinese: 长生 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
This is the situation to begin with.
White makes a throw in at
White has the option of making 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 External references
49th Honinbo league, game two
Warp: In game two of the 49th Honinbo league between Rin Kaiho (Black) and Komatsu Hideki, played on 1993-09-02, a very curious eternal life variant involving a ko happened, which resulted in the game being voided. I think it was called an "eternal ko". The position leading to this happened in the lower left corner (it's Black's turn, after exchanging
Black captures the ko with
Now, after White captures the ko with
Instead of
The game was declared void . . . Robert Pauli: . . . but the game point nevertheless was split.
C[Game ruled no result due to eternal \ ko, and each player awarded 1/2 point. Time used: \ W 4h 59m \ B 4h 59m ]
Couldn't Rin have filled 'a' (instead 'e') to settle the corner (. . . 'b', 'c', pass, and 'e')? No, he would have lost by half a point! (Many thanks to Nando for correcting my false beliefe due to a flawed diagram in DGoZ 10/93.)
Above, each side has 143 stones on the board, so each side has made the same amount of captives. Black counts 50 points (pretending the white stones in the lower left being dead), White 42 (ignoring his false eye), but since Black has to add three stones ('a', 'c', and 'e') and give 5.5 points komi, that's not enough.
You can find a game record at
By the way, it's no coincidence that all ko threats were gone. To avoid losing by 0.5 points, Rin had to play hane in the upper left corner, leading to a game-deciding minimal ko there. After 22 flips (254 - 317) Komatsu played his second to last ko threat, in the lower left corner (1-1). Rin ignored it, filled the upper left ko, and . . . you know the rest of the story - unbelievable. 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. ![]() |