Xuanxuan Qijing Problem 21: White to play and kill
玄玄棋经 · Problem 21 of 347 · First-line hane and sacrifice
Black's corner and the stones on the top depend on each other. Start on the first line, and be ready to give up stones to break the link between them.
How to solve it
This problem is known as 'Unstable Behavior' (德二三). Black's stones in the corner and on the top are only thinly linked. White starts with the hane at F19 on the first line.
If Black defends at D17, White extends to E19 and Black blocks at D19. White pushes in at C17, and Black captures the two stones on the edge with G19. White continues with C18, answered at C19, and C16. After A19, A17 and Black's connection at F19, White's D18 splits Black for good: neither the corner nor the stones on the top can make two eyes.
If Black answers the hane at D18 instead, White plays C17 and, after Black's C18, reduces the corner with A17, answered at A18, and B19. Black cannot make two eyes.
Main line
- 1. White F19
- 2. Black D17
- 3. White E19
- 4. Black D19
- 5. White C17
- 6. Black G19
- 7. White C18
- 8. Black C19
- 9. White C16
- 10. Black A19
- 11. White A17
- 12. Black F19
- 13. White D18
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.