Life In 19x19

Life in 19x19. Go, Weiqi, Baduk... Thats the life.
https://lifein19x19.com/

Why only after two black moves is white dead?

https://lifein19x19.com/viewtopic.php?t=12220

Page 1 of 2

Re: Why only after two black moves is white dead?

Posted: Wed Aug 26, 2015 12:38 pm
by skydyr
paullik wrote:
skydyr wrote:
paullik wrote: Since they are inside white's territory, right?
Yes, in a sense, but do you understand why it's white's territory now and not before?
Because it's only now that the :bc: are surrounded.
Well...
Click Here To Show Diagram Code
[go]$$B Seki
$$ -------------------
$$ | . X X X . 2 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
In this diagram, black's three stones are also surrounded, but they're alive in seki. So what's the difference between the this one and the following that makes it different?
Click Here To Show Diagram Code
[go]$$W White lives outright
$$ -------------------
$$ | . X X X . . 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]

Re: Why only after two black moves is white dead?

Posted: Wed Aug 26, 2015 1:21 pm
by paullik
skydyr wrote: Well...
Click Here To Show Diagram Code
[go]$$B Seki
$$ -------------------
$$ | . X X X . 2 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
In this diagram, black's three stones are also surrounded, but they're alive in seki. So what's the difference between the this one and the following that makes it different?
Click Here To Show Diagram Code
[go]$$W White lives outright
$$ -------------------
$$ | . X X X . . 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
The number of liberties of the white stones, which in fact lead to seki or to killing the three black stones.

Re: Why only after two black moves is white dead?

Posted: Wed Aug 26, 2015 2:03 pm
by skydyr
paullik wrote:
skydyr wrote: Well...
Click Here To Show Diagram Code
[go]$$B Seki
$$ -------------------
$$ | . X X X . 2 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
In this diagram, black's three stones are also surrounded, but they're alive in seki. So what's the difference between the this one and the following that makes it different?
Click Here To Show Diagram Code
[go]$$W White lives outright
$$ -------------------
$$ | . X X X . . 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
The number of liberties of the white stones, which in fact lead to seki or to killing the three black stones.
Well, if black plays here:
Click Here To Show Diagram Code
[go]$$W White lives outright
$$ -------------------
$$ | . X X X 2 . 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
Isn't the number of liberties the same as before? White has 5 liberties in this and the other diagram.

Re: Why only after two black moves is white dead?

Posted: Wed Aug 26, 2015 4:28 pm
by Joaz Banbeck
http://senseis.xmp.net/?DeadEyeshapes

Re: Why only after two black moves is white dead?

Posted: Thu Aug 27, 2015 6:37 am
by gowan
In this diagram
Click Here To Show Diagram Code
[go]$$W White lives outright
$$ -------------------
$$ | a X X X 2 b 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
White has three "outside" liberties so white can play at a and b (if necessary) so in the end the shape will be
Click Here To Show Diagram Code
[go]$$W White lives with territory
$$ -------------------
$$ | O . . . . O O X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
The empty points inside White's group make four in a line which is alive.

If Black plays first as in the next diagram, White lives in seki, as do the three surrounded black stones.
Click Here To Show Diagram Code
[go]$$B White lives in seki (no territory)
$$ -------------------
$$ | . X X X . 2 1 X .
$$ | O O O O O O O X .
$$ | . O . X X X X X .
$$ | X O O . X . . . .
$$ | X O X X X . . . .
$$ | . X . . . . . . .
$$ | . X . X . . . . .
$$ | . . . . . . . . .[/go]
So in either case, White lives. In one case White gets points, in the other no points, but White lives in both cases.

Re: Why only after two black moves is white dead?

Posted: Thu Aug 27, 2015 6:44 am
by paullik
gowan wrote: So in either case, White lives. In one case White gets points, in the other no points, but White lives in both cases.
I wouldn't have thought about this, since I was still looking at the problem from the point where black dies or not, not considering the fact that white remains alive.

Posted: Thu Aug 27, 2015 9:10 pm
by EdLee
Off topic:
I was still looking at... not considering...
Hi Paul,

Isn't it nice that Go teaches us...
To:
  • Look more deeply (not just the surface);
  • Look more broadly (the big and bigger pictures);
  • Look at not only our own situation, but our opponent's;
  • See the reality as it is (objectively; not subjectively, biased by our blindness, selfishness, over-confidence, cowardice, convenience, prejudices, jealousy, anger, stupidity, immaturity, impatience, greed, etc.)
:)

( The same can be said about chess, many genuine martial arts, and other disciplines. :mrgreen: )
All times are UTC-07:00
Page 1 of 2

Powered by phpBB® Forum Software © phpBB Limited