Xuanxuan Qijing Problem 16: Black to play and kill
玄玄棋经 · Problem 16 of 347 · Shortage of liberties
White's eyes have to come from the top edge. Find the middle of that space, and check whether White can atari your stones from either side.
How to solve it
White's eyes have to come from the top edge. Black plays in the middle of that space at E19.
If White answers at F19, Black plays D18, and after White's C19 Black finishes with G19. White cannot approach the black stones from either side because of a shortage of liberties, so there is no second eye.
If White answers at C19 instead, Black again plays D18. White pushes at E18 and Black plays F19. White can capture a stone with D19, but after Black's G19 White still cannot make two eyes.
Main line
- 1. Black E19
- 2. White F19
- 3. Black D18
- 4. White C19
- 5. Black G19
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.