Xuanxuan Qijing Problem 37: White to play and make a ko
玄玄棋经 · Problem 37 of 347 · Creating a shortage of liberties
White's centre stones are racing against the black group above them. Count first: simply taking away Black's eye loses by a move. Look for moves that cost Black liberties on both sides.
How to solve it
This problem is titled 'Eight Dragons Ascend to Heaven' (八龍昇天勢). White has to save the stones in the centre, which are in a capturing race with the black group above them. Simply taking away Black's eye loses the race, so White first has to reduce Black's liberties.
White plays J18 and, after Black's K18, L18. Together these two moves make Black short of liberties. Black answers at L17, and White exchanges J17 for J16.
White's M19 is the next key move. Black captures it with L19, White plays H19 on the other side, and Black answers at J19. White captures with K19, Black with N19, and White plays F19.
Black is now short of liberties on both sides and is forced to fight a ko.
Main line
- 1. White J18
- 2. Black K18
- 3. White L18
- 4. Black L17
- 5. White J17
- 6. Black J16
- 7. White M19
- 8. Black L19
- 9. White H19
- 10. Black J19
- 11. White K19
- 12. Black N19
- 13. White F19
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.