TFG9 Black Upper Left

    Keywords: Life & Death
[Diagram]
Starting situation  



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

What if Black just connects?

[Diagram]
Black connects  

Black has two liberties on the left while White has four at the top - White wins.



[Diagram]
Hanging connection  

B5 at W2

Again, Black has two liberties to White's four - White wins.

[Diagram]
Something else  

W10 at B7

If next Black a, White b, Black has only three liberties.



[Diagram]
More serious 1  

This B1 eliminates the opportunity for White to throw in here and squeeze Black. White plays W2 to spoil Black's eye but when she answers B3 with W4, Black sets up a ko for life on the left with the opportunity to capture White in the upper center still open. White can't win this way.



[Diagram]
More serious 2a  



  • W4 is a strong play
  • If B5, White answers with W6 which threatens to cut at W10 and at the same time reduces Black to one eye. If Black tries to cut at B7, White answers at W8. If Black persists with B9, W10 sets ups a situation where Black is in shortage of liberties on both sides ( Black a, White b). White can capture the left side stones before Black can free himself at the top.
[Diagram]
More serious 2b  



  • Black varies to B7 to prevent White from cutting at a.
  • So White turns to the upper side to increase her liberties.
[Diagram]
More serious 2c  



  • W8 forces B9
  • So when White plays W10, the inner shapes are the same on both sides, but White is one move ahead, winning the fight and the game.
[Diagram]
More serious 3  



If Black tries to prevent White's eye-spoiling move with B5, W6 makes miai of the points marked a and b; so Black collapses. Note that playing W6 at a lets Black make ko with a throw-in at W6.


REVISION!

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

[Diagram]
More serious 2c - revised  



Continuing from 2b, Black plays B1 instead of the original B3. When White throws in at W2, Black extends at B3. Although White takes the stone at W4, the space inside her group is much smaller than in the original line and she ends up with only five liberties. She has the ko but since the real issue is the survival of the black group on the left, Black has more ko threats than White.

[Diagram]
More serious 2d - B lives!  

W4 at white+circle. After B5, Black is two moves from capturing the white stones while on the left White is four moves away from capturing the black stones. Black also has the internal ko threats of a and b. White'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 Black doesn't start with the black+circle/white+circle exchange?

Good luck!

[Diagram]
What other tries does Black have?  

Arno: the points marked as a suffer from a follow-up play White b which will lead to the capture of the crucial black+circle stone. That way White will increase her liberties and whatever Black tries, he will fail.

But there exists another line: TFG9 Black Upper Left 2.


TFG9 Black Upper Left last edited by Unkx80 on April 17, 2004 - 21:59
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