[computer-go] Life and Death

[Tom Cooper]

I think that the original description of the position should have said
'killable' rather than 'dead', and that David missed the fact that
it is White to move.

At 08:06 27/03/2008, Hideki wrote:

>David Fotland: <17fc01c88fdc$5ad98100$108c8300$@com>:
> >I just looked at this position and it looks like a win for black in the
> >first position.  Many Faces evaluates it as a win for black, and plays c1 to
> >save the lower left black group with almost no thinking time.
> >
> >Mogo is correct because the lower left black group is not dead.
>
>I'm sorry if wrong but the black seems dead by B5 after C1, isn't
>it?
>
>-Hideki
>
> >David
> >
> >> -----Original Message-----
> >> From: computer-go-bounces at computer-go.org [mailto:computer-go-
> >> bounces at computer-go.org] On Behalf Of Matthew Woodcraft
> >> Sent: Sunday, March 09, 2008 11:49 AM
> >> To: computer-go
> >> Subject: [computer-go] Life and Death
> >>
> >> I've included two 13x13 positions below. In both positions it is
> >> Black's
> >> move.
> >>
> >> The first position is simplified from a real game. Black has two
> >> enclosed dead groups, and White has a small but easy win.
> >>
> >> The second position is a modified version of the first in which the
> >> dead
> >> groups are more obviously dead.
> >>
> >> If I try MogoRelease3 playing as Black on position 2, it shows a 20%
> >> score and resigns either immediately or after a couple of moves.
> >>
> >> If I try it on position 1, it shows a score of 70%+ for Black, and
> >> continues to play until White takes steps to remove the dead groups
> >> from
> >> the board. I've tested with up to 2^24 playouts.
> >>
> >> I have tried increasing --collectorLimitTreeSize and --limitTreeSize
> >> (like bigMogo in the scalability study), but I can't set them much
> >> higher than the default on this machine without running out of memory.
> >>
> >> I'd be interested to see if someone with a bigger computer can find out
> >> what resources it needs to judge this position well, and to see how
> >> other engines do.
> >>
> >> Position 1
> >>
> >> (;GM[1]FF[4]
> >> CA[UTF-8]
> >> SZ[13]
> >> HA[0]
> >> KM[0.5]
> >> AB[jb:kb][cb:cc][kc][bd:cd][jd:ld][be][he][cf:df][bg][gb:gh]
> >> [ig:ih][jh:kh][eg:ei][li][aj:bj][hi:hj][lk][al][ck:cl][ji:jl]
> >> [dm][im]
> >> AW[ia:ja][ib][hc:jc][db:dd][hd:id][ce:de][ie][ke:le][bf][hf:jf]
> >> [lf][jg:kg][mg][lh][ai:di][gi][mi][cj][ej:gj][ij][dk:fk][hk:ik]
> >> [dl][il][bm][fl:fm][hm]
> >> )
> >>
> >> Position 2
> >>
> >> (;GM[1]FF[4]
> >> CA[UTF-8]
> >> SZ[13]
> >> HA[0]
> >> KM[0.5]
> >> AB[jb:mb][cb:cc][kc][bd:cd][jd:md][be][he][cf:df][bg][gb:gh]
> >> [ig:ih][jh:kh][eg:ei][li][aj:bj][hi:hj][bk:ck][lk][al][cl]
> >> [ji:jl][im]
> >> AW[ia:la][ib][hc:jc][mc][db:dd][hd:id][ce:de][ie][ke:le][bf]
> >> [hf:jf][lf][jg:kg][mg][lh][ai:di][gi][mi][cj][ej:gj][ij][dk:fk]
> >> [hk:ik][dl][fl][il][bm:cm][em:fm][hm]
> >> )
> >>
> >> -M-
> >> _______________________________________________
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> >> computer-go at computer-go.org
> >> http://www.computer-go.org/mailman/listinfo/computer-go/
> >
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>--
>gg at nue.ci.i.u-tokyo.ac.jp (Kato)
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