Xuanxuan Qijing Problem 39: Black to play and kill
玄玄棋经 · Problem 39 of 347 · Double-purpose move on the first line
Two white groups are weak, but so is the link between Black's own stones. Find one move that mends Black's weakness and threatens both groups at once.
How to solve it
This problem is titled 'Meet at the Source from Left and Right' (左右逢源勢). Two white groups are short of eyes, and Black's stones between them have a cutting point at F18. Black's G19 on the first line does two jobs: it protects that cut, and it aims at both B17 and K18, each of which kills one white group.
If White pushes at F18 anyway, Black captures a stone with E16. White has to save the group on the left with B17, and Black plays K18 against the other one.
White's only hope is then to cut off Black's stones on the edge, and every attempt fails: J19 is met by J18, H19 by H18, J18 by J19, and both H18 and G18 by J18.
The shape move G18 also looks at both sides, but it does not work: White plays B17, and Black's K19 is answered at K18.
Main line
- 1. Black G19
- 2. White F18
- 3. Black E16
- 4. White B17
- 5. Black K18
- 6. White J19
- 7. Black J18
- 8. White H18
- 9. Black H17
- 10. White G18
- 11. Black 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.