Re: [gnugo-devel] Gnu Go 3.2 possibly correctable flaw in play

[Stéphane Nicolet]

> On Fri, 25 Jul 2003 address@hidden wrote:
>
> > I noticed a possibly correctable flaw in Gnu Go 3.2 opening strategy. 
> >  The
> > SGF file below shows the problem with Gnu Go's opening.  I can use 
> > the same flaw
> > to give Gnu Go 6 stones and still win, even though I'm not that good. 
> >  This
> > trick of sacraficing a couple of stones to waste a lot of the 
> > programs stones
> > works against Swiss Explorer and Goliath also, but doesn't work 
> > against human
> > players.  This looks to me like a straightforward flaw that might not 
> > be too
> > hard to fix.
>
> Thanks for pointing this out; it is indeed a problem.  The latest
> development versions are less susceptible to this, but only somewhat.  
> You
> might try gnugo 3.3.23 for a stronger version; alternately, 3.4 should 
> be
> out in a couple weeks.
> I'm not sure how easy to fix this will be, but it definitely needs
> attention; thank you for the report.
> Evan Daniel


Version 3.3.23 with the cosmic patch seems to solve the problem
in that particular game, because it puts more emphasis on creating
moyos in the beginning of the game. Look for instance at the moves
it proposes between 6 and 18 :

Move 2 (white): GNU Go plays D16 (75.00) - Game move D16 (75.00)
Move 4 (white): GNU Go plays Q5 (25.08) - Game move Q16
Move 6 (white): GNU Go plays R5 (44.98) - Game move D17 (23.21)
Move 8 (white): GNU Go plays C5 (40.41) - Game move Q17 (23.89)
Move 10 (white): GNU Go plays C5 (45.61) - Game move P18 (19.58)
Move 12 (white): GNU Go plays E12 (33.23) - Game move P16 (31.86)
Move 14 (white): GNU Go plays C12 (30.65) - Game move E18 (17.16)
Move 16 (white): GNU Go plays R12 (31.85) - Game move E16 (22.71)
Move 18 (white): GNU Go plays F12 (30.58) - Game move F17 (23.83)
Move 20 (white): GNU Go plays M17 (36.25) - Game move G18 (23.33)
Move 22 (white): GNU Go plays O12 (32.12) - Game move C12 (29.02)
Move 24 (white): GNU Go plays D12 (45.60) - Game move D12 (45.60)
Move 26 (white): GNU Go plays H11 (41.21) - Game move H17
Move 28 (white): GNU Go plays F11 (38.01) - Game move F11 (38.01)
Move 30 (white): GNU Go plays G10 (48.98) - Game move G10 (48.98)
[..]


Stephane.