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.


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.


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.

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:

                  / \
                 1   B
                    / \
                   1  ...

That is equal to 1 plus this infinitesimal,

                  / \
                 0   B
                    / \
                   0  ...

which is called, over.

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

-- Bill Spight

HachiriTomoko? : I wonder why suicide does not make much sense? For example in here:


(White to play) If there is no suicide then black wins, but if there is suicide then white can play the (only) suicide move and then it can win!

No Pass Go/Suicide last edited by HachiriTomoko on May 15, 2022 - 13:10
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