[Bug-gnubg] GeneralCubeDecisionE, cubeinfo.fMove, and aarOutput[0][6]

[David Montgomery]

Hi,

I'm getting results I don't understand from a call to GeneralCubeDecisionE.
I'm hoping someone can help me understand them.

Here's the position:

 GNU Backgammon  Position ID: eN8PAAADAAAAAA
                 Match ID   : AQHgAEAAGAAA
 +12-11-10--9--8--7-------6--5--4--3--2--1-+     O: Oh (Cube: 2)
 |                  |   |                O | OOO 4 points
 |                  |   |                O | OOO On roll
 |                  |   |                  | OOO
 |                  |   |                  | OO
 |                  |   |                  | OO
^|                  |BAR|                  |     7 point match
 |                  |   | 6  X             |
 |                  |   | X  X  X          |
 |                  |   | X  X  X          |
 |                  |   | X  X  X          |
 |                  |   | X  X  X          |     3 points
 +13-14-15-16-17-18------19-20-21-22-23-24-+     X: Ex
Pip counts: O 2, X 77


My understanding of GeneralCubeDecisionE is that:

output[0][6] gets the cubeful equity assuming that the roller doesn't
double, and
output[1][6] gets the cubeful equity assuming that the roller doubles and
the non-roller takes.

But for this position I get
output[0][6] = 0.1598 if cubeinfo.fMove = 0, or
output[0][6] = 0.3792 if cubeinfo.fMove = 1.

The board I'm passing to GeneralCubeDecisionE has O (oh) is player 0 (zero).
So,  if fMove == 0, I would expect output[0][6] = 0.
And, if fMove == 1, I would expect output[0][6] = 0.945*0.169188 = 0.1598
(Zadeh).

>From this, I can see that fMove==0 is giving me the result I
expect for fMove==1 (though I don't know why), but I don't have
any idea where .3792 is coming from.

Also, the cubeless numbers in aarOutput[0 or 1][0-4] seem to always
be as though player 1 is on roll, regardless of fMove.

I would very much appreciate any help clearing up my confusion.

Thanks,
David

P.S.: Details below:

Here is exactly what I get:

aarOutput
[0]
        [0] 0.00000000
        [1] 0.00000000
        [2] 0.00000000
        [3] 0.055558100
        [4] 0.00000000
        [5] -1.1039084 OR -1.0437878 (corresponding to fMove = 0, fMove = 1)
        [6] 0.15978776 OR 0.37917596
[1]
        [0] 0.00000000
        [1] 0.00000000
        [2] 0.00000000
        [3] 0.055558100
        [4] 0.00000000
        [5] -1.1039084 OR -1.0437878
        [6] 0.00000000

Below are the parameters I'm calling with.

cubeinfo
        nCube           2
        fCubeOwner      0
        fMove           1 OR 0
        nMatchTo        7
        anScore
                [0]     3
                [1]     4
        fCrawford       0
        fJacoby         0
        fBeavers        0
        arGammonPrice
                [0]     1.8702656
                [1]     0.78814477
                [2]     1.8977833e-008
                [3]     0.00000000

evalcontext
        bCubeful        1
        nPlies          0
        nReduced        0
        bDeterministic  1
        rNoise          0.00000000


gnuBoard
[0]
        [0]     2
        [1]     0
        [2]     0
        [3]     0
        [4]     0
        [5]     0
        [6]     0
        [7]     0
        [8]     0
        [9]     0
        [10]    0
        [11]    0
        [12]    0
        [13]    0
        [14]    0
        [15]    0
        [16]    0
        [17]    0
        [18]    0
        [19]    0
        [20]    0
        [21]    0
        [22]    0
        [23]    0
        [24]    0
[1]
        [0]     0
        [1]     0
        [2]     0
        [3]     4
        [4]     5
        [5]     6
        [6]     0
        [7]     0
        [8]     0
        [9]     0
        [10]    0
        [11]    0
        [12]    0
        [13]    0
        [14]    0
        [15]    0
        [16]    0
        [17]    0
        [18]    0
        [19]    0
        [20]    0
        [21]    0
        [22]    0
        [23]    0
        [24]    0