Gokyo Seimyo Volume 3 Problem 13 / Attempts
![[Diagram]](../../diagrams/17/0fa09ee566d9cd947d33aef9d8c9470a.png)
Apperent vital point?
![[Diagram]](../../diagrams/16/5fffb243a71b59fccc3ec036b72e220e.png)
Refutation
![[Diagram]](../../diagrams/38/abaa3199fa38d0e4b636624bc7799738.png)
Refutation? or big ko?
![[Diagram]](../../diagrams/22/608840d166a85f1e1cc860ddccb7a002.png)
Necessary forcing move
White should force with 1 first. Black must choose a, b, or c to avoid immediately sacrificing the two stones in the corner.
![[Diagram]](../../diagrams/48/55fcf7ece8adaa898bcf7c033ef8e61a.png)
Black loses 2 stones
After the sequence to 4 black is short of liberties, and must give up at least two stones in the corner. Black does get sente here, and this is the best he can do.
![[Diagram]](../../diagrams/21/d56f46efbe95a9504eaa747dfbcd4a57.png)
Black loses 2 stones
Normally this ko will be too serious for black to fight. Move 1 at 5 will lead to the same ko.
![[Diagram]](../../diagrams/27/9c43b08bba31bd9aeedd79a89728b149.png)
Final result
This result is 3 points better, but it is gote, and sente will usually be worth more.