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.



BQM 442 last edited by 96.239.19.23 on July 10, 2021 - 16:20
RecentChanges · StartingPoints · About
Edit page ·Search · Related · Page info · Latest diff
[Welcome to Sensei's Library!]
RecentChanges
StartingPoints
About
RandomPage
Search position
Page history
Latest page diff
Partner sites:
Go Teaching Ladder
Goproblems.com
Login / Prefs
Tools
Sensei's Library