Xuanxuan Qijing Problem 54: Black to play and make a ko
玄玄棋经 · Problem 54 of 347 · Two-stone sacrifice and throw-in
Black cannot live in the corner outright. Give up two stones on the first line, then keep playing back into the space they leave behind.
How to solve it
Black's stones in the corner cannot live as they stand, but they can get a ko. Black starts with C19 on the first line. White answers at C18, Black adds a second stone at B19, and White captures both with A19.
Black now plays B16 on the outside, and White answers at C15.
Black throws in at B19. White captures with C19, Black plays A18, White captures again with A17, and Black's A16 makes the corner a ko.
Main line
- 1. Black C19
- 2. White C18
- 3. Black B19
- 4. White A19
- 5. Black B16
- 6. White C15
- 7. Black B19
- 8. White C19
- 9. Black A18
- 10. White A17
- 11. Black A16
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.