Two-Headed Dragon

    Keywords: Life & Death

Chinese 1: 假眼活 (jia3 yen3 huo2, literally "false eye life")
Chinese 2: 兩頭蛇 (liang3 tou2 she2, literally "two-headed snake")
Japanese: 欠け眼生き (kakeme iki)

[Diagram]

Example 1

A Two-Headed Dragon (also known as Dragon Eats its Own Tail) is an unusual method of creating a living group. A Two-Headed Dragon is a group that has two eyes that are at first sight false eyes, nevertheless these two eyes are enough for living. To get this position, the group has to be a ring around some living group of an opponent, as in this diagram. Because the eyes are connected to each other in both directions, White cannot play at either of them first, and thus they function as real eyes, even though they have all the looks of false ones [1]. In actual play, these positions are extremely rare but not non-existent.

You can download a [ext] game containing a two-headed dragon.

Two other examples, one a game from the 20th World Amateur Championship and one a go problem, are [ext] located on the GoGoD site.


More examples

[Diagram]

Example 2

[Diagram]

Example 3

Note: Black is the one with the Two-Headed dragon (or maybe a "Four-Headed dragon"!)

[Diagram]

Example 4

[Diagram]

Example 5

Note: One of the chains making the Two-Headed dragon may be reduced to a single stone.


See also


This is a copy of the living page "Two-Headed Dragon" at Sensei's Library.
(OC) 2014 the Authors, published under the OpenContent License V1.0.
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