Xuanxuan Qijing Problem 26: Black to play and live
玄玄棋经 · Problem 26 of 347 · Squeeze without the throw-in
Sacrifice two stones in the corner to squeeze White. Then be careful: the move that usually follows a capture like that is a mistake here.
How to solve it
The Chinese name of this problem is 四門斗底勢, a battle formation from the 16th-century novel Fengshen Yanyi. Black's group has to find its eyes in the corner and starts a squeeze with B18 and A18. White answers at B19 and captures the two stones with A19.
After a capture like this the usual move is a throw-in back at B18. Here it does not work. Black plays D19 instead: the tesuji is not to throw in.
White attacks from below with B15, Black blocks at B16, White plays A16 and Black plays C19. White can capture a stone with A14, but then Black captures two stones with B18 and, after White's A15, two more with A18. White is short of liberties and cannot stop Black from making two eyes.
Starting with B19 fails: White takes B18, and after Black's B16 and White's A19 the result is a ko.
Main line
- 1. Black B18
- 2. White B19
- 3. Black A18
- 4. White A19
- 5. Black D19
- 6. White B15
- 7. Black B16
- 8. White A16
- 9. Black C19
- 10. White A14
- 11. Black B18
- 12. White A15
- 13. 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.