Tesuji And Anti Suji Of Go / Errata

Table of contents Table of diagrams
Connecting underneath
Sakata's solution
Continuation
Variation in the book
Variation 1
Connecting underneath
Variation 2
Problem diagram: Black to kill
Main variation
Second variation
Third variation
Third variation: a question mark
Third variation: cont.
Third variation: cont.


Page 35 diagrams 12 through 15

Various thoughts on the suji of connecting underneath

Dieter: I think that it is better for Black to immediately cut at 3 in diagram 13. If White captures, this reverts to diagrams 14 and 15. If White extends, Black connects. In the latter case, he has not made the exchange 1-2 in diagram 12 and thus not given away a stone for free.

Diagrams:

[Diagram]

Connecting underneath

Problem: How to connect the three isolated black stones to the corner ?

[Diagram]

Sakata's solution

[Diagram]

Continuation

After B7, White can't connect at a because of shortage of liberties.

[Diagram]

Variation in the book

So White will extend with W4 and Black connects underneath.


Now for my suggestion:

[Diagram]

Variation 1

Dieter: I think that it is better for Black to cut immediately with B1 here.

[Diagram]

Connecting underneath

If White captures, this reverts to Sakata's solution.

[Diagram]

Variation 2

If White extends, Black connects. If we compare this result to the variation in the book, we see that in the latter Black makes the exchange of a for White b, a loss of two points compared to Black b - White a.


Page 38-39 diagrams 9 through 14

[Diagram]

Problem diagram: Black to kill

[Diagram]

Main variation

White is in shortage of liberties at a and b. Everything OK up until here.

[Diagram]

Second variation

The second variation, presented as "if White makes the diagonal attachment of W2", shows an extra stone black+circle . If black+circle is in place, B3 at a still works. When it is not in place, too. This is just awkward but not really inconsistent.

[Diagram]

Third variation

The third variation, White connecting at W2, requires a tesuji, namely B3, creating shortage of liberties. However, this is only necessary when black+circle is not in place. With black+circle in place, Black can play B3 at B5 immediately.

[Diagram]

Third variation: a question mark

White can't play at a: she is already in shortage of liberties!

[Diagram]

Third variation: cont.

The circled point is now empty. Now White can play at a.

So B5 is better at a, making ko. --BillSpight

[Diagram]

Third variation: cont.

Therefore, Black exchanges B3 for W4 and only then does he cut at B5. Now White is unable to play at a because of shortage of liberties.


Variation 2 being awkward, and the comments in variation 3 being inconsistent with the diagram, it is my opinion that black+circle should not be in place in diagrams 12, 13 and 14.

-- DieterVerhofstadt (1k)


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