Tsumego From Games 20
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Keywords: Problem
This came up today in a game. White thought that the group in the corner is alive. Is this so? --unkx80
![[Diagram]](../../diagrams/43/ab9d1ef874fbfe3899d3f6b335c71b22.png) | Status? (All outer stones are alive) |
![[Diagram]](../../diagrams/52/6300dde2e932c72458db786ce8e240a5.png) | What happened during the game |
During the game, Black played . After , a and b are miai, and White is killed by shortage of liberties. White resigned soon after that.
![[Diagram]](../../diagrams/51/2b8cb2a5b7f6128096a061e24a1f2c2e.png) | Also dead |
provides another path of resistance. However, up to the , White is dead in bulky five. It does not matter if is played at first.
But--
![[Diagram]](../../diagrams/45/251063a7a3f4a11182ce243b8c6253d4.png) | Correct play by White |
The descent by is the correct move which both players failed to see. To stop White from connecting underneath Black may play at , but then ensures life. After that, a and b are miai.
![[Diagram]](../../diagrams/33/a9258dbef95be4296977a06646ef841f.png) | The actual solution |
The real solution is actually the placement at . The best sequence is from to , which results in a rogue ko.
Dieter: the - exchange makes it a rectangular six in the corner with one outside liberty. In that case, the 1-2 point makes it ko.
![[Diagram]](../../diagrams/31/183896bff3b975a186bae9bff9c7fc3d.png) | Not as good |
followed by is yet another variation. Up to , it is still a ko, but the ko is worse off for White compared to the previous diagram.
Bill Spight: A wonderful position, unkx80!
Because of the throw-in the ko is unusual, but this case has another quirk, thanks to the local ko threat to connect. I'll discuss this further at rogue Ko.
unkx80: Thanks. But shamefully, I was Black.
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"Tsumego From Games 20" at
Sensei's Library.
2004 the Authors, published under the OpenContent License V1.0.
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