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Re: A rather violent game. (9 kyu vs 10 kyu)
Posted: Sat May 28, 2011 7:27 am
by jts
I have the feeling I should simply forbid myself from playing on the second line until turn 50 or so, unless joseki calls for it.
Yes! And also, play more slowly. If you use up 30 minutes in the first 100 moves, instead of 10 minutes, you could solve these l&d problems during the game.
Re: A rather violent game. (9 kyu vs 10 kyu)
Posted: Sun May 29, 2011 5:48 am
by cyclops
Bill Spight wrote:Sevis wrote:I think 250 leads to a ko:
$$Wc
$$ -------------
$$ | 4 3 1 . X . .
$$ | 5 2 6 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
$$ -------------
$$ | 4 3 1 . X . .
$$ | 5 2 6 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
$$Wc
$$ -------------
$$ | . 2 1 . X . .
$$ | 4 3 . X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
$$ -------------
$$ | . 2 1 . X . .
$$ | 4 3 . X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
I think that

makes a better ko for Black, as a rule.

Accidentally I pushed the "i like this post" button when I intended to quote the post. But as a rule I like Bill's posts, so no harm done.
Although the discussion might be obsolete because of the solutions of Illuck/Mitsun as a rule it pays off to think about the meaning of Bill's contribution. Why is his ko better. I think it is because Sevis' 6 is wrong because it allows white to connect and have a bent four. With 6 sevis should play a ko threat that he should win to make the approach move at 6. After that he needs to fight the ko for a second time. So the ko is a 2 step ko for black and one step for white. As a rule this is worse than the 1 step ko in Bill's diagram. "as a rule" probably means that usually the profit pays off but in exceptional cases it might not.
Re: A rather violent game. (9 kyu vs 10 kyu)
Posted: Sun May 29, 2011 8:49 am
by Bill Spight
Sevis wrote:Bill Spight wrote:Sevis wrote:Thank you for the comments, everyone.
I had indeed noticed a ridiculous number of weaknesses that were left over, but attacking some more seemed like a better idea at the time. I'll try to get a game against a stronger player up sometime soon.
I think 250 leads to a ko:
$$Wc
$$ -------------
$$ | 4 3 1 . X . .
$$ | 5 2 6 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
$$ -------------
$$ | 4 3 1 . X . .
$$ | 5 2 6 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
$$Wc
$$ -------------
$$ | . 2 1 . X . .
$$ | 4 3 . X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
$$ -------------
$$ | . 2 1 . X . .
$$ | 4 3 . X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
I think that

makes a better ko for Black, as a rule.

Why would this be a better ko?
$$Wc

elsewhere
$$ -------------
$$ | 4 O O . X 3 .
$$ | 1 X X X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
elsewhere
$$ -------------
$$ | 4 O O . X 3 .
$$ | 1 X X X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
It seems to me, that in this variation, after white has one the ko once, he must win it again, as it takes three moves to kill.
$$Wc

elsewhere
$$ -------------
$$ | 1 . O . X . .
$$ | X O 3 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
elsewhere
$$ -------------
$$ | 1 . O . X . .
$$ | X O 3 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
Here, everything is clearly dead.
Correct play depends upon the ko threat situation and the size of other plays. When this was played -- after White missed the kill! (Thanks, mitsun.

) --, I do not think that White should take the ko before filling the dame.
$$Wc
$$ -------------
$$ | X O O . X 1 .
$$ | 3 X 2 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .
- Click Here To Show Diagram Code
[go]$$Wc
$$ -------------
$$ | X O O . X 1 .
$$ | 3 X 2 X X O .
$$ | X X X O X O O
$$ | O O O O O . .
$$ | . . . . . . .
$$ | . . . . . . .[/go]
The ko is still for the life or death of the Black group, and White takes first, but ths ko is better for White than the other ko because of

if Black wins the ko.
Note also that if White does not continue the ko at this point, it takes Black two moves to win the ko.