Xuanxuan Qijing Problem 50: White to play and kill
玄玄棋经 · Problem 50 of 347 · Double snapback
Black's two chains each have a weak spot. Make Black defend both, and then look for one move that puts both chains in atari at once.
How to solve it
White first plays H15 and G15, which Black has to answer at H16 and G16: if any white stone connected out, Black would not have enough eye space.
White then plays E14, answered at D14, and F14. Both black chains are now in atari, so Black has to capture on one side.
Whichever side Black captures, White throws in again and both chains are in atari once more. Black is caught in a double snapback and dies.
The exchange of E14 for D14 can also be played first. Starting with G15 fails: Black answers at H15, and after E14 and D14 Black has two ways to make the second eye.
Main line
- 1. White H15
- 2. Black H16
- 3. White G15
- 4. Black G16
- 5. White E14
- 6. Black D14
- 7. White F14
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.