OD1P - May 23 Problem / Solution

Sub-page of OD1PMay23Problem

Summary

Anonymous summary...

[Diagram]

IT'S ALIVE

Black lives (without ko.)

[Diagram]

Bad for white (can't play at a)

[Diagram]

3 is Tesuji

Best for white. If W4 at W6, then B5 at B7. If W4 at a, then black makes life with B5, (although he might make bigger life with B6?)

[Diagram]

Inferior 4 (B9 at black+circle)

Trying to kill only lets black get bigger life.

[Diagram]

Bad for white

B3 saves the day again. W4 at W8 transposes to our previous line. If W4 at B5, then B5 at W4 makes B8 and a miai.

[Diagram]

Double ko

Even if white has infinite ko threats, black is alive. White never gets a chance to fill a, because black can always take one of the kos, and thus threatening to make unconditional life by taking the other.

[Diagram]

Ko

Black makes a ko for life.

[Diagram]

Ko (not small)

B7 captures This is (probably?) the best way for black to play after B1.

[Diagram]

Ko (continued)

Black takes first.

[Diagram]

B3 is too greedy

This B3 fails, since W8 at B1 kills.

[Diagram]

o_O

I am unsure how white counters this B3. a, b, c, and d are possibilities. After other moves, black makes life with d.

[Diagram]

Dead

W2 and W4 are sente, W6 takes the vital point.

[Diagram]

This B1 dies too

[Diagram]

Bulky five, so B1 dies

[Diagram]

This B1 seems to transpose into other lines...?


This might work

[Diagram]

Black lives, I hope...

Black lives.

[Diagram]

I think this would be white's response...

This looks like black dies... the real solution is at the 2-2 point, as shown below? --Anon


Failure 1 (Dead)

[Diagram]

Failure 1 (Dead)

Black dies.


Failure 2 (Ko - Black can do better)

[Diagram]

Failure 2 (Ko)

B7 takes at black+circle. Next:

[Diagram]

Failure 2 (continued)

W1 takes back, and after B2 and W3 a ko fight ensues. Black can do better than that.


[Diagram]

How about?

B7 takes at black+circle, W8 at 2.
Bill: The writer was under the misapprehension that B7 could be played at 2. The corrected sequence shows that Black dies.

[Diagram]

Or? (4 at 2, 7 at white+circle)


[Diagram]

Or? (Corrected.)

W4 fills at black+circle.
Bill: Through B7 Black lives, but W4 is an error.


Attempt 3

[Diagram]

Atari

Bill: B1 looks OK.
Then W2 - B7 is sente.
In a real game, I think that the ko (Failure 2) is often better than giving up so much for small life. :-)

[Diagram]

Double ko

Here is a variation I like. Black is alive in double ko.


B1 was a real blind spot for me. I had then expected W2 here, and Black still lives.

[Diagram]

Solution 3



This is a copy of the living page "OD1P - May 23 Problem / Solution" at Sensei's Library.
(OC) 2009 the Authors, published under the OpenContent License V1.0.
[Welcome to Sensei's Library!]
StartingPoints
ReferenceSection
About