Re: [Bug-gnubg] G/BG rates [minor ?]

[Joern Thyssen]

On Mon, Sep 08, 2003 at 12:16:09PM +0200, address@hidden wrote
> 
> 
> Hi all,
> 
> I do the following :
> 
> - evaluate a position (anyone where market window make sense/is allowed)
> 
> - write down the static, 1 ply and 2 ply [Win, W(g), W(bg)] percentages
> 
> - open the "Market Window Analyzer" and try to see if the indicated gammon
>   and backgammon rates matches the ones you can compute manually
> 
> EXAMPLE :
> 
> This is the output of the Evaluation :
> 
>   Position ID: 4HPiQSDgc/ABMA
>   Match ID:    cAngAAAAAAAA
> 
>   Evaluator:   CONTACT
> 
>   <SNIP ... SNIP>
> 
>           Win     W(g)    W(bg)   L(g)    L(bg)   Equity    Cubeful
>   static:  48,46%  13,86%   0,41%  13,49%   0,72%  -0,0304   -0,0458
>    1 ply:  50,32%  14,01%   0,50%  12,90%   0,48%  +0,0186   +0,0232
>    2 ply:  48,58%  13,59%   0,44%  13,58%   0,63%  -0,0305   -0,0436
> 
> Now I was expecting :
> 
> gammon rate (static) = 13.86/48.46 = 28.60%
> gammon rate (1 ply)  = 14.01/50.32 = 27.84%
> gammon rate (2 ply)  = 13.59/48.58 = 27.97%

Note as well as Win includes W(g) and W(bg), W(g) includes W(bg), so I'd
expect:

gammon rate (static) = (13.86-0.41)/48.46 = 27.75%
gammon rate (1-ply)  = (14.01-0.50)/50.32 = 26.85%
gammon rate( 2-ply)  = (13.59-0.44)/48.58 = 27.07%

I guess the small differences to the ones calculaetd by the market
window is due to rounding errors.

> 
> But in the "Market Window Analyzer" GNUbg shows :
> 
> gammon rate (static) = 27.75%
> gammon rate (1 ply)  = 26.87%
> gammon rate (2 ply)  = 27.04%
> 
> Small (not so small in fact) differences exists for backgammon rates
> too, no matter the ply and for both players. 

I wouldn't expect any difference on the bg percentages, except those who
can be attributed to rounding errors. For example,

bg rate( static) = 0.50/48.46 = 0.10%


ørn

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