Four die but six live

    Keywords: Life & Death, Proverb

On the third line or in the corner on the second line a string of four stones is dead, and a string of six stones is alive. A string of five stones lives or dies according to sente.


[Diagram]

Four stones on the third line die

Black tries to expand his eyespace with B1 and B3, but White plays W2 and W4 and Black dies. B3 at a or B5 is met with W6.


[Diagram]

Six stones on the third line live

When Black has six stones in a row, White can not kill the stones. W1-W7 fails after B8.

Bill: W7 doesn't look too good to me. How about Wa or Wb?

SGBailey: W7' at a appears to be handled by B8' between a and 6. There are potential throw-ins and other complicated stuff depending what path White wriggles with.

[Diagram]

Death

Bill: I think White can kill, then.

[Diagram]

Seki

Bill: Black can make ko, but seki is normally better, no?

SGBailey: W7' at b gets B8' at a.

Bill: Right. :-)


Can someone show how to live or kill with five ?

Isn't this an application of the above? With 5, whomever has sente can effectively reduce it to 4 or expand to 6. No?


Slowman: How about this? (Please check it :-))

[Diagram]

Five stones on the third line : B sente

[Diagram]

variation: 6 at 9

[Diagram]

5 dies

zephi? Unfortunately, 5 on the 3rd line dies even if b has sente. After 6, b can't get 2 eyes. (note: playing b5 one space to the left doesn't work either)

[Diagram]

5 dies

nachtrabe: Sure that isn't a seki?

Chris Hayashida: W6 at B7? Then when the outside liberties are filled, White can atari from the inside and make a bulky five shape, killing Black.


SGBailey: The comb formation lives.

[Diagram]

Try this B sente for size.



This is a copy of the living page "Four die but six live" at Sensei's Library.
(OC) 2005 the Authors, published under the OpenContent License V1.0.
[Welcome to Sensei's Library!]
StartingPoints
ReferenceSection
About