Yes, O being closed out has no move decisions to make, and is far from
double or re-doubling if he takes - so such positions were not part of the
training.

On Wed, Aug 26, 2009 at 7:45 PM, Massimiliano Maini <[email protected]>wrote:

> >
> >De : Joseph Heled <[email protected]>
> >
> >That is why getting a strong 0-ply is of the utmost importance.
> >I am not sure what is the state of other bots.
>
> We do agree on this, getting a strong 0ply NN is a must.
> Actually that's why I was inquiring to know if the training
> methodology of gnubg NN could be responsible of this kind of
> behavior.
>
> This whole odd/even effect thing seems to be much more visible
> in gnubg than in other bots and it's the source of (possibly wrong)
> beliefs like "gnubg 3ply cube is worse/better than 2ply cube"
> or "2ply cube is worse/better than 3ply cube for closed out
> positions" etc.
>
> In the particular position (which is an extreme case):
>
>    GNU Backgammon  Position ID: DwAAsN22AYgAAA
>                    Match ID   : MAHgAAAAAAAA
>    +-1--2--3--4--5--6-------7--8--9-10-11-12-+  O: gnubg
>    | O  O  O  O  O  O |   |                  |  0 points
>    | O  O  O  O  O  O |   |                  |  On roll
>    |    O             |   |                  |
>    |                  |   |                  |
>    |                  |   |                  |
>    |                  |BAR|                  |^ 7 point match (Cube: 1)
>  X |                  |   |                  |
>  XX | X                |   |                  |
>  XX | X                |   |                  |
>  XX | X                | X |                  |
>  XX | X              O | X |       O          |  0 points
>    +24-23-22-21-20-19------18-17-16-15-14-13-+  X: MaX
>
> O on roll:
> Position ID: DwAAsN22AYgAAA
> Match ID: MAHgAAAAAAAA
> Evaluator:  Crashed
>        Win     W(g)    W(bg)   L(g)    L(bg)   Equity    Cubeful
> static:  76.8     0.0     0.0     0.1     0.0    +0.534    +0.785
>  1 ply:  88.0     0.0     0.0     0.1     0.0    +0.759    +0.923
>  2 ply:  79.7     0.0     0.0     0.1     0.0    +0.593    +0.999
>  3 ply:  87.7     0.0     0.0     0.0     0.0    +0.754    +1.000
>  4 ply:  82.0     0.0     0.0     0.0     0.0    +0.639    +1.000
>
> BGBlitz has:
>
> O on move:   (Plies are starting with 1, so it's gnubg 0/1/2-ply)
>
> 1-ply  Green        83.0  0.0   0.0
>
> 2-ply  Green        81.9  0.0   0.0
>
> 3-ply  Green        84.4  0.0   0.0
>
>
> So BGBlitz too has some swinging between odd and even plies, but
> the amplitude is 2-4%, not 12%. Snowie seems to behave like BGBlitz,
> just 2-3% swing.
>
> MaX.
>
>
>
>
>
>
_______________________________________________
Bug-gnubg mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/bug-gnubg

Reply via email to