Xuanxuan Qijing Problem 88: Black to play and live
玄玄棋经 · Problem 88 of 347 · Sacrifice, first-line crawl and the eye before the capture
Black can put White's stones on the top side in atari, but taking them is not the whole answer. Count Black's eyes after the capture. Is there a move that should come first?
How to solve it
Black starts with the sacrifice at G18. White gives atari with H18, Black plays J18, and White captures with G19. Black descends to J19 and White connects at H19. White's stones on the top side are now short of liberties.
Black then crawls along the first line: E19, D19, C19 and B19, while White pushes above with E18, D18 and C18. White adds C17, Black extends to F19, which puts the white stones on the top side in atari, and White plays B17. A commenter on Sensei's Library calls the whole sequence a one-way street.
Now Black can capture five stones with G18, but that is the mistake. Sensei's Library shows the result: White plays A18 and Black is left with two false eyes.
The correct move is A18 first. It makes an eye in the corner, and the white stones are still in atari, so capturing them later gives Black the second eye.
Main line
- 1. Black G18
- 2. White H18
- 3. Black J18
- 4. White G19
- 5. Black J19
- 6. White H19
- 7. Black E19
- 8. White E18
- 9. Black D19
- 10. White D18
- 11. Black C19
- 12. White C18
- 13. Black B19
- 14. White C17
- 15. Black F19
- 16. White B17
- 17. Black A18
Solution checked against Sensei's Library.
Play it out on the board
Place the stones yourself and see the refutation when you miss. All the Xuanxuan Qijing problems as quick lessons.