Protect Both Sides in the Corner

Path: <= Endgame =>
    Keywords: EndGame, Tesuji
[Diagram]

The hane-connect in this diagram is a well known endgame play.

White will now usually defend at a, b, or perhaps c.

However, in the corner, there is sometimes a better option.


Setup

[Diagram]

Consider this corner.

White plays hane and connects, and black must defend the cut now.

How?


Wrong answer

[Diagram]

B4 is wrong, as is the move at a.

[Diagram]

After B4, white can play another hane-connect, W5-W7, in sente. Black needs B8 (or b) to defend again.


Right answer

[Diagram]

The right answer is to play B4. This not only defends against the cut at a, it also makes the hane at b gote for black.

With B4, black protects both sides with one move.


Caution

The technique shown only works in limited situations where B4 is not too far away from the cut, and is close to the other hane.

Some examples where it fails:

[Diagram]

Too far away

[Diagram]

Still too far away

Note the tesuji W8!

[Diagram]

Not sufficiently protected

[Diagram]

Doesn't work two ways

B11 at a, W12 at b

[Diagram]

Double atari

It is also, of course, important to check for other weaknesses related to the cut, such as this one.


Path: <= Endgame =>
This is a copy of the living page "Protect Both Sides in the Corner" at Sensei's Library.
(OC) 2016 the Authors, published under the OpenContent License V1.0.
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