Re: [Bug-gnubg] Strange cubeless rollout result?

[Joern Thyssen]

On Wed, Jan 08, 2003 at 03:32:46AM -0500, address@hidden wrote
> Hi
> I set up the following position and wanted to roll it out CUBELESS.
> 
> Position ID     vHsXAADCNhQCNw
> Match ID    MAEAAAAAAAAA
> 
> So I selected:
> Settings---Options---uncheck "use doubling cube"
> However I *forgot* to uncheck "use Jacoby rule"
> 
> First question:
> 
> If I'm doing a cubeless rollout, then I want G and B to count, so why do I 
> still need to uncheck "use Jacoby rule" ? 

Because gnubg *always* does rollouts "according to score" (he he, unlike
snowie4 that never does that). That is, it uses the gammon price based
on the current score and cube value. I can see this is confusing for
money game.

So a cubeless moneygame rollout with Jacoby rule is equivalent to a
rollout for a 1-pt match. I'll consider changing this :-)


> Compared to the other three Bots GNU didn't do so well at 0-ply.

Gary is trying to hunt down a possible bug in the rollout code.

> The thing that did appear strange was the BG figure.
> 
> GNU(24.6) SW3.2(13.0) JF(13.6) SW4(12.8).

because gammons and backgammons don't count, gnubg won't try to save
gammon and backgammon, for example:

 GNU Backgammon  Position ID: AgAA7LYdAIAAAA
                 Match ID   : cIkKAAAAAAAA
 +13-14-15-16-17-18------19-20-21-22-23-24-+     O: gnubg
 |                  |   |             O  X | OOO 0 points
 |                  |   |                  | OOO 
 |                  |   |                  | OOO 
 |                  |   |                  | OOO 
 |                  |   |                  | OO 
v|                  |BAR|                  |     (Cube: 1)
 |                  |   |                  |    
 |                  |   |                  |     
 |                  |   | X           X    |     
 |                  |   | X  X  X  X  X  X |     Rolled 52
 |                  |   | X  X  X  X  X  X |     0 points
 +12-11-10--9--8--7-------6--5--4--3--2--1-+     X: jth


    1. Cubeful 0-ply    24/19 6/4                    Eq.:  -1,000
       0,000 0,000 0,000 - 1,000 1,000 1,000
        0-ply cubeful [expert]
    2. Cubeful 0-ply    24/19 5/3                    Eq.:  -1,000 ( +0,000)
       0,000 0,000 0,000 - 1,000 1,000 1,000
        0-ply cubeful [expert]
    3. Cubeful 0-ply    24/19 4/2                    Eq.:  -1,000 ( +0,000)
       0,000 0,000 0,000 - 1,000 1,000 1,000
        0-ply cubeful [expert]
    4. Cubeful 0-ply    6/1 3/1                      Eq.:  -1,000 ( +0,000)
       0,000 0,000 0,000 - 1,000 1,000 0,981
        0-ply cubeful [expert]


Jørn