Xuanxuan Qijing Problem 39 / Solution

Table of contents

First problem

Solution

[Diagram]

Solution

B1 is a double purpose move. It protects the cut at 'a', so now black is aiming at either 'x' or 'y' to kill one of white's groups.

[Diagram]

White's resistance

The purpose of playing W2 is that W2 offers some help when white tries to cut B1 and B5 off from the black group outside.

If W2 at 'a', black 'b' is good enough (see diagram at the end of this section).

[Diagram]

White's resistance cont.

Because of black+circle, there's no eye at 'x'; the only chance for white to live is to kill some black stones.

Next, let's look at these white resistances one by one, from 'a' to 'e'.

Resistance 'a'

[Diagram]

After B4, white is not able to protect both weakness at 'x' and 'y'.

[Diagram]

Attempt to connect underneath fails, too. (B6 at 'y' works, but B6 here is a little better.)



Resistance 'b'

[Diagram]

W1 doesn't do much in terms of cutting.

Resistance 'c'

[Diagram]

Black can connect with either 'x' or 'y'.

Resistance 'd'

[Diagram]

Next black has either 'x' or 'y'.

White 'k' next is also responded by black 'y'.

Resistance 'e'

[Diagram]

After B4, white can't get both 'x' and 'y'.



Alternative White resistance

[Diagram]

Alternative White resistance: 1

Here White resists with white+circle. After 1, White must protect with 2, otherwise the group on the right dies if Black gets to play at 2. Then Black kills the other group with 3. White's resistance with 4 and 6 doesn't work.

[Diagram]

Alternative White resistance: 2

After 7 in the previous diagram White can't capture the black+circle stones as the white+circle stones have too many cutting points.




Another Good Move

[Diagram]

Very often B1 is a good move that looks at both sides.

In this case, it doesn't work.

[Diagram]

In some cases when white is strong around and black is trying to make two eyes, B1 can be a good move that aims at either 'x' or 'y' next.




Variant problem

[Diagram]

Failure

In this variant problem, the main line sequence fails.

[Diagram]

Failure

The position of the black+circle stone gave White an extra liberty, so the sacrifice of four White stones from W2 onwards is possible. As a result, Black only managed to capture four White stones.

[Diagram]

Solution

The solution is then to make a placement at B1 first. If W2 blocks, then B3 and B5 enables B7, capturing the group on the right side.

[Diagram]

Solution

If W2 here, then B3 makes W4 and B5 miai.


This is a copy of the living page "Xuanxuan Qijing Problem 39 / Solution" at Sensei's Library.
(OC) 2014 the Authors, published under the OpenContent License V1.0.
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