Four die but six live / analysis

Sub-page of FourDieButSixLive

Table of diagrams
Six stones on the third line live
Death
Seki
Life
Life
Isn't B6 better than a?
Invasion
Small life
White keeps sente
White keeps sente?
Five stones on the third line : B sente
variation: 6 at 9
5 dies
Reply to zephi
5 dies
Actually seki
Try this B sente for size.
Aim at the vital point first
seems alive

[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 white a or white b?

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?

[Diagram]

Life

Bill: (Much later.) B2 lives, doesn't it? W3 and B4 are miai.

torij?: Actually, if white wants to do something it is better to play W1 at B2 and make a gote seki. Since playing here is gote for either side, black most like as not lives in endgame.

Robert Pauli: torij, it's a sente seki (see main page).



[Diagram]

Life

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

Bill: Right. :-)
W1 seems to be White's best play.

Robert Pauli: No, torij was right.


Kevin?: Title says 'Six Live' but these sequences only show death or seki for black. Quite confusing.

Bill: The sequence that Steve and I discussed last had no diagram. I just put it in, along with another diagram for life. Besides, seki is a form of life.

[Diagram]

Isn't B6 better than a?



[Diagram]

Invasion

Bill: No. W3 is the key point. W9 captures the black+circle stones.

[Diagram]

Small life



[Diagram]

White keeps sente

Robert Pauli: W5 should connect. This results in the seki shown here, with White keeping sente, not loosing it. That's certainly worth a point less.

[Diagram]

White keeps sente?

Bill: But if Black now plays B6?

Robert Pauli: White pushes ahead on the second line, not? If there's no escape, nothing has changed essentially (besides that pushing from behind is bad).


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]

Reply to zephi

Slowman: Another sequence is B1 W5 B4, still ok for black.

[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.

kevinwm: The shape shown first is a sente seki for w. Playing 6 at 7 makes it death. Stones 8 and 9 below are miai for seki.

[Diagram]

Actually seki



SGBailey: The comb formation lives.

[Diagram]

Try this B sente for size.

[Diagram]

Aim at the vital point first

torij?: The gote move of 4 in SGBailey's diagram seems to be the wrong approach. Aiming for the vital point before playing a hane is key. Black has a difficult time answering this because 'a' becomes a ko and anything that doesn't reduce white's liberties will allow white to play 'b'.

[Diagram]

seems alive

hnishy: live by oshitsubushi (B11 at a), isn't it?



This is a copy of the living page "Four die but six live / analysis" at Sensei's Library.
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