No Pass Go/Suicide

Sub-page of NoPassGo

Suicide does not make much sense with no pass go, since playing a one stone suicide is equivalent to passing, and multiple stone suicide is worse. However, there is some theoretical interest in the game, at least, with Ing-style suicide, which does not allow one stone suicide. Some new infinitesimals appear.

[Diagram]
Superko  

W3 @ white+circle, B4 @ black+circle

No pass go with suicide can lead to some strange superkos. If W1 captures black+circle, B2 will capture white+circle and win. After W1 plays suicide, if B2 plays in his two point eye, W3 will capture black+circle and win. So B2 plays suicide, as well. Now if W3 plays in her two point eye, Black will win. So play leads to a superko.

[Diagram]
Infinitesimal  

How do we evaluate this board? White's territory is worth -1, but what about Black's? Black to play moves to a territory worth 1. White to play plays suicide, to yield the next position.

[Diagram]
Infinitesimal (ii)  

Here, too, Black can play to a territory of 1, while White can play to the previous position.

The game tree looks like this:

                   A
                  / \
                 1   B
                    / \
                   1  ...

That is equal to 1 plus this infinitesimal,

                   A
                  / \
                 0   B
                    / \
                   0  ...

which is called, over.

The very small advantage that Black has on these two boards is over.

-- Bill Spight


No Pass Go/Suicide last edited by Bill on April 15, 2008 - 16:38
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