Xuanxuan Qijing Problem 81: Black to play and kill
玄玄棋经 · Problem 81 of 347 · Three-stone sacrifice and three-point nakade
White's stones on the top side have very little room, but Black's stone next to them is short of liberties too. Do not try to save it. How many stones would White have to capture, and what shape would that leave?
How to solve it
White's group on the top side has little room for eyes. Black starts by pushing in at E18. If White plays G19, Black descends to E19 and White answers at F19.
Black then takes away the eye space on the right with J19, J18, K18. White fills the outside liberties with D18 and D19, with K19 played in between, and Black's H19 puts the whole white group in atari.
White can only capture Black's three stones on the left. Black plays back at E18, the middle of the three empty points, and White is dead by three-point nakade, as Sensei's Library puts it.
If White answers the first move at E19 instead, Black plays the hane at G19. After G18, J18, D18 and H19, White has no room for two eyes. Sensei's Library warns that D19 instead of G19 is a careless mistake: White plays G19 and gets a ko.
Main line
- 1. Black E18
- 2. White G19
- 3. Black E19
- 4. White F19
- 5. Black J19
- 6. White J18
- 7. Black K18
- 8. White D18
- 9. Black K19
- 10. White D19
- 11. Black H19
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.