Home > Steve > Go > Problem of the month
This problem is from a position which occurred in a game at the 13*13 small board championship this month. In the game Black died in the corner. Can he live - in seki, ko or directly? Can he kill the white top edge group?
This problem is typical of the sort of mess I end up with in my games.
I am not certain of the completeness of this answer, but all I can find for black is kos and sekis. If anyone knows of a living with territory sequence, please let me know. There are many sequences for Black to die!
As Dia 2 shows, A Black descent on the left to 1 requires a response on the left - White 2' at 3 being the move. It makes an eye and requires black to make approach moves to capture the white stones.
Again the other white stones get capture when Black bends to the right with 1 here, requiring a reply such as 2' at 3.
Black 3 and 5 easily make a ko. White 6 takes the ko the first time round and, if the threat is ignored, can play 8 at A to make Black's life worse. If playing at 8 isn't good for White then he can just atari the four black stones.
If Black is short of ko threats then he can play for a seki. Not that this gives Black a ko threat for another fight - capturing 6 & 10 requires white to throw in again there to maintain the seki.
Kefeng Chu pointed out Black 1 here which lets Black capture the top white stones and live with his corner ones. The white stones on the right then have the option of running away.
Why didn't I see this when writing this up? Or better yet in the game?
Problem of the month
British Go Association
Last updated 2005-06-11
This page is part of http://www.stocton.org/