[Welcome to Sensei's Library!]

StartingPoints
ReferenceSection
About


Referenced by
TFG9PlayingHane
TFG9BlackUpperLeft2

 

TFG9 Black Upper Left
   

[Diagram]
Diag.: Starting situation


First let's look at some simple questions... DaveSigaty

What if B just connects?

[Diagram]
Diag.: Black connects

B has 2 liberties on the left while W has 4 at the top - W wins.

[Diagram]
Diag.: Hanging connection

B 5 at 2

Again, B has 2 liberties to W's 4 - W wins.

[Diagram]
Diag.: Something else

W 10 at 7

If next B 'a', W 'b', B has only 3 liberties.

[Diagram]
Diag.: More serious 1

This B 1 eliminates the opportunity for W to throw in here and squeeze B. W plays 2 to spoil B's eye but when she answers 3 with 4, B sets up a ko for life on the left with the opportunity to capture W in the top center still open. W can't win this way.

[Diagram]
Diag.: More serious 2a


  • W 4 is a strong play
  • If B 5, W answers with 6 which threatens to cut at 10 and at the same time reduces B to one eye. If B tries to cut at 7, W answers at 8. If B persists with 9, W 10 sets ups a situation where B is in damezumari on both sides ( B 'a', W 'b'). W can capture the left side stones before B can free himself on the top.

[Diagram]
Diag.: More serious 2b


  • B changes to 7 to prevent W from cutting at 'a'
  • So W turns to the upper side to extend her liberties.

[Diagram]
Diag.: More serious 2c


  • W 8 forces B 9
  • So when W plays 10 the inner shapes are the same on both sides but W is one move ahead, winning the fight and the game.

[Diagram]
Diag.: More serious 3

If B tries to prevent W's eye spoiling move with 5, W 6 makes miai of the points marked 'a' and 'b' so B collapses. Note that playing 6 at 'a' lets B make ko with a throw in at 6.



REVISION!

The variation in 2c above needs to be revised to reflect an improvement for B found on TFG9 - White At The Top.

[Diagram]
Diag.: More serious 2c - revised

Continuing from 2b, B plays 1 instead of the original 3. When W throws in at 2, B extends at 3. Although W takes the stone at 4, the space inside her group is much smaller than in the original line and she ends up with only 5 liberties. She has the ko but since the real issue is the survival of the B group on the left, B has more ko threats than W.


[Diagram]
Diag.: More serious 2d - B lives!

W 4 at the marked stone. After 5, B is two moves from capturing the W stones while on the left W is 4 moves away from capturing the B stones. B also has the internal ko threats of 'a' and 'b'. W's position is hopeless.



Someone else's turn to post a few lines!

  • What are the refutations for the 'a' points below?
  • Are there other lines as well?
  • What if B doesn't start with the marked exchange?

Good luck!

[Diagram]
Diag.: What other tries does B have?


Arno: the points marked as 'a' suffer from a follow up play by white 'b' which will lead to the capture of the crucial marked B stone. That way white will extend her liberties and whatever B tries, he will fail.

But there exists another line: TFG9 Black Upper Left 2



This is a copy of the living page "TFG9 Black Upper Left" at Sensei's Library.
(C) the Authors, published under the OpenContent License V1.0.