RE: [Bug-gnubg] Re: 0-ply cube

[Albert Silver]

I can't because as Michael said, "I haven't shown the positions because
they are not relevant." Thus I have not seen them. I'll resend this with
my Hotmail address to him as he doesn't receive mail from my main e-mail
address for some reason.

                                                Albert

> -----Original Message-----
> From: address@hidden [mailto:bug-gnubg-
> address@hidden On Behalf Of Joseph Heled
> Sent: Saturday, June 07, 2003 5:53 PM
> To: Albert Silver
> Cc: gnubg
> Subject: [Bug-gnubg] Re: 0-ply cube
> 
> I don't have a gammonline account. Can I see some of the positions
please?
> 
> -Joseph
> 
> 
> 
> 
> Albert Silver wrote:
> > Hi,
> >
> > I'm sending this via direct e-mail as opposed to the GNU mailing
list
> > because the post is in HTML and I'm not sure whether the mailing
list
> > would preserve this in a readable format. Michael Depreli posted the
> > following in GoL regarding some very strange GNU behaviour in 0-ply
cube
> > decisions which I am sending to you.
> >
> >
> > Albert
> >
> >
> > Examples Of GNU 0-ply cube oddness.
> >
> > Posted By: Michael Depreli <address@hidden>
> > Date: Saturday, 7 June 2003, at 3:07 a.m.
> > Here's some evidence that GNU 0 ply cube is unreliable for Double/No
> > Double decisions.
> > These were the first three double/no double decisions from one of
the
> > money sessions between SW and GNU and nearly all the others I looked
at
> > suffer from the same peculiarities. I haven't shown the positions
> > because they are not relevant.
> > Notice the No/Double & Double/Take equities are always identical and
in
> > fact GNU never doubles
> > regardless of whether it's an optional double or not. S4's 1ply (GNU
0
> > ply Equiv) is shown in red.
> >
> >
> >
> > Cube decision
> >
> > 0-ply cubeless equity
> > +0.509
> >
> >
> >
> > 0.635 0.297 0.014 - 0.365 0.070 0.001
> >
> > Cubeful equities:
> >
> > 1.
> > No double
> > +0.770
> >
> >
> > 2.
> > Double, pass
> > +1.000
> > +0.230
> >
> > 3.
> > Double, take
> > +0.770
> > +0.000
> >
> > Proper cube action:
> > Optional double, take
> > SW4: 0.687/0.774
> >
> >
> > Cube decision
> >
> > 2-ply cubeless equity
> > +0.514
> >
> >
> >
> > 0.634 0.304 0.019 - 0.366 0.075 0.002
> >
> > Cubeful equities:
> >
> > 1.
> > Double, take
> > +0.780
> >
> >
> > 2.
> > Double, pass
> > +1.000
> > +0.220
> >
> > 3.
> > No double
> > +0.634
> > -0.146
> >
> > Proper cube action:
> > Double, take
> > SW4: 0.683/0.784
> >
> >
> > Cube decision
> >
> > 0-ply cubeless equity
> > +0.535
> >
> >
> >
> > 0.669 0.266 0.009 - 0.331 0.076 0.001
> >
> > Cubeful equities:
> >
> > 1.
> > No double
> > +0.846
> >
> >
> > 2.
> > Double, pass
> > +1.000
> > +0.154
> >
> > 3.
> > Double, take
> > +0.846
> > +0.000
> >
> > Proper cube action:
> > Optional double, take
> >  SW4: 0.738/0.853
> >
> > Cube decision
> >
> > 2-ply cubeless equity
> > +0.548
> >
> >
> >
> > 0.674 0.263 0.010 - 0.326 0.071 0.001
> >
> > Cubeful equities:
> >
> > 1.
> > Double, take
> > +0.874
> >
> >
> > 2.
> > Double, pass
> > +1.000
> > +0.126
> >
> > 3.
> > No double
> > +0.794
> > -0.080
> >
> > Proper cube action:
> > Double, take
> >  SW4: 0.792/0.882
> >
> >
> > Cube decision
> >
> > 0-ply cubeless equity
> > +0.599
> >
> >
> >
> > 0.654 0.340 0.026 - 0.346 0.074 0.002
> >
> > Cubeful equities:
> >
> > 1.
> > No double
> > +0.962
> >
> >
> > 2.
> > Double, pass
> > +1.000
> > +0.038
> >
> > 3.
> > Double, take
> > +0.962
> > -0.000
> >
> > Proper cube action:
> > No double, take (0.0%)
> >  SW4: 0.667/0.741
> >
> > Cube decision
> >
> > 2-ply cubeless equity
> > +0.550
> >
> >
> >
> > 0.636 0.338 0.027 - 0.364 0.083 0.003
> >
> > Cubeful equities:
> >
> > 1.
> > Double, take
> > +0.853
> >
> >
> > 2.
> > Double, pass
> > +1.000
> > +0.147
> >
> > 3.
> > No double
> > +0.761
> > -0.093
> >
> > Proper cube action:
> > Double, take
> >  SW4: 0.692/0.721
> >
> >
> >
> > Re: Examples Of GNU 0-ply cube oddness.
> >
> > Posted By: Ilia Guzei <address@hidden>
> > Date: Saturday, 7 June 2003, at 3:32 a.m.
> > In Response To: Examples
> > <http://www.gammonline.com/members/board/config.cgi?read=54891> Of
GNU
> > 0-ply cube oddness. (Michael Depreli)
> > Michael,
> > I am not sure how much trust one can put into the cube evaluations
at
> > low plies. Often S4 doubles at its 2-ply level but reverses the
decision
> > at the 3-ply level by a significant margin. The 1-ply level is
probably
> > even less reliable.
> > Also note how different the equities reported by Snowie and GNUBG
are. I
> > still wonder why the two bots produces equity differences of such
> > magnitude.
> > Ilia
> >
> >
> > Re: Examples Of GNU 0-ply cube oddness.
> >
> > Posted By: Michael Depreli <address@hidden>
> > Date: Saturday, 7 June 2003, at 6:15 a.m.
> > In Response To: Re: Examples
> > <http://www.gammonline.com/members/board/config.cgi?read=54892> Of
GNU
> > 0-ply cube oddness. (Ilia Guzei)
> > I'm already on record as stating I would never use GNU 0-ply or SW
1-ply
> > for evaluating cube decisions.
> > I posted these example because I still see rollouts posted here
using
> > 0-ply cube which I really don't trust.
> > To be honest I don't actually know the overall effect it has on
rollouts
> > but it can't be good when these positions show GNU 0-ply refuses to
> > double!
> > Sure S4 changes it's decision from 2 to 3 ply because it's another
ply
> > of accuracy with sound mathematical doubling formulae behind it.
> > My guess is S4 1-ply uses a simplistic cubeless to cubeful
conversion
> > and bases it's decision around some borderline level, which although
not
> > good enough for serious stundents IMHO at least looks more sensible
than
> > GNU's attempt.
> > I guess if you analaysed a huge number of cube decisions you could
come
> > up with a cubeless equity which would average out being borderline
for
> > double/no double decsion. Maybe even some of Janowski's formula
could
> > improve on this method.
> > Michael
> >
> >
> 
> 
> 
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