BQM 442

  Difficulty: Advanced   Keywords: EndGame

A problem from two different 7x7 Go investigations.

[Diagram]

what is Blacks best move?

In 7x7 Go b is mentioned as best move. While on an [ext] SGF about the same problem a is given as best move.

Please high ranking Go players tell me (12 kyu) what is best.

[Diagram]

The throw-in

Dieter: I am no expert, but here's what I see. Black's throw in forces an extra move inside White's territory later.

[Diagram]

If White inadvertently covers the neutral points, Black has the tesuji of B9 to create seki.

[Diagram]

Simple descent

If Black simply descends, White gains a point with W4. So I'm inclined to vote for the throw-in.

[Diagram]

Ko

White has a countermeasure though. So, I must think again.


willemien Hi Dieter Thanks for your reply. according to the [ext] Tromp sgf the following is best

[Diagram]

Tromps Continuation (1) 6 at white+circle, 9 at 2

[Diagram]

Tromps Continuation (2) 3 at white+circle, 21 at white+square


your remark about the neutral points is valid white needs to add a stone inside his territory so loses a point under territory rules (and this way the problem becomes an wholeboard endgame problem


lightvector: Edit from years later in the future! (2021)

[Diagram]

Possible Refutation of throwin

KataGo suggests that the throw-in may be actually completely unplayable for black, because white has this placement to cause trouble next. The immediate threat is the cut at "a", Black must defend it somehow.

[Diagram]

Possible Refutation of throwin, followup 1

I have not analyzed the variations, but this way for example black is coming under liberty issues while white threatens to live in the corner.

[Diagram]

Possible Refutation of throwin, followup 2

Against a more solid black defense, white does go ahead and start the ko, using the lower right for ko threats.



This is a copy of the living page "BQM 442" at Sensei's Library.
(OC) 2023 the Authors, published under the OpenContent License V1.0.
[Welcome to Sensei's Library!]
StartingPoints
ReferenceSection
About