Quoting Sanghyeon Seo <[EMAIL PROTECTED]>:
2007/6/14, Magnus Persson <[EMAIL PROTECTED]>:
Quoting Sylvain Gelly <[EMAIL PROTECTED]>:
> Hi Darren,
>
> After white (mogo) H2, MoGo was estimating 74%, and expecting:
> H2 G1 H3 B1 A1 B3 H1 F8 B5 H4
> Then black played H3, and estimation increased to 81%, white B3 and
> expecting:
> B3 B1 A1 B4 C5 C4 A3 C6 B6 B5
This sequence is a disaster for Mogo because the position after B5 is
trivially lost.
Agreed.
But the error is white A3 in this variation. Normally making an eye
is good in
the semeai, and in random playouts it is a winning move in this
position. But
here it gives black time to win the semeai against the stones which are not
protected by the eye.
B3 B1 A1 B4 C5 C4 >B5< instead captures the black stones right away if
I am not blind to something. [Valkyria wants to play C6 instead of C5 which
also seems to win easily]
This is correct, but the error in the line is black B4. Black would
approach from G1 and black wins the semeai.
You are right so after B1 (which black must play to make G1 work) then
G1 is the
only move.
Still the fight turns to the upper side after white lives and now
white has a
chance to live but plays A7 at move 50, but if white plays C9 for life it is
very close, but if my analysis is correct then black wins with 0.5 after
threatening a seki in the corner. [Valkyria misunderstands this position
completely because of the seki in the corner so I could not use it.]
Agreed about move 50 at C9, but can black win after that? I guess
threatening seki means A8 after C9, then:
(first move white, move 50)
C9 A8 A7 F9 E9 A6 B8 C6 A9 is forced.
Then J3 J2 H4 finishes the game, and B1 A4 D1 A2 are dame. This is a
half point win for white. Did I miss something?
This is fun! GoGui thinks that black wins 0.5 with chinese rules and 0.5 with
Japanese rules! So what rules was the tournament played with and what
rules did
the programs implement... or am I confused? I have to admit that I am
unaware on
under which circumstances the rule sets differ.
Mogo fills in its own liberties in order to kill the group of
Steenvreter, but
dies and loose the semeai. It is possible for Mogo to live by
throwing in with
A9 but then Black will win with a kofight which involves white trying
to invade the upper right group as kothreats. This fight was a matter of a
single liberty as well...
I don't understand this part. After black E9 white throws in A9 and A8
C9 lets white unconditionally alive. However in my counting this is a
half point loss for white.
Agree. Note that I also wrote it was a half point win for black so you might
have mixed up the colors of what I wrote or what you did write. From what you
wrote I think we have the same conclusion. But I am not 100% sure of this last
analysis on my part, but on the other hand normally MoGo should find a 0.5 win
easily at this stage. Minor remark: I was wrong about the final kofight since
black can simply skip by decending at J3 as you did above which normally is a
bad move.
--
Seo Sanghyeon
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--
Magnus Persson
Berlin, Germany
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