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Re: [Bug-gnubg] 0-ply cubeful equities
From: |
Joern Thyssen |
Subject: |
Re: [Bug-gnubg] 0-ply cubeful equities |
Date: |
Tue, 10 Jun 2003 09:44:14 +0000 |
User-agent: |
Mutt/1.4.1i |
On Tue, Jun 10, 2003 at 05:12:25AM -0400, address@hidden wrote
> They look much better. I noticed 0-ply doubles medium races too soon.
> Does the race net simply play the checker properly or should I
> generate a bearoff database.
No, the race net is almost as good as bearoff databases, so that's
probably a waste of time.
> Can 0-ply access some other input to cube these properly?
A 0-ply cube decision has no way to calculate market losers or the
volatility of a position, so put very simple: it doubles when it's
Y% into the market window.
Y is related to the cube efficiency X used in Janowski's formula. For
races we calculate X as
#define RACEFACTOR 0.00125
#define RACECOEFF 0.55
#define RACE_MAX_EFF 0.7
#define RACE_MIN_EFF 0.6
rEff = anPips[1]*RACEFACTOR + RACECOEFF;
if (rEff > RACE_MAX_EFF)
return RACE_MAX_EFF;
else
{
if (rEff < RACE_MIN_EFF)
return RACE_MIN_EFF;
else
return rEff;
}
}
so X is between 0.7 and 0.6 depending on the length of the race. When I
have some spare time I can calculate what Y that corresponds to.
Jørn