[Bug-gnubg] Post-Crawford 2-away opening 41 for leader

[Ian Shaw]

GnuBg thinks that after an opening 41, Leader should use the free drop. 
However, if I give Leader the cube on 2, GnuBg says that Leader is over 50% to 
win. If this is the case, then Leader should be taking.
My test does not change the depth of the search, so what is going on?

    GNU Backgammon  Position ID: 4HPwATDgc/ABMA
                    Match ID   : MAFGABAAAAAA
    +-1--2--3--4--5--6-------7--8--9-10-11-12-+  O: Leader
    | X              O |   |    O           X |  1 point
    | X              O |   |    O           X |  Rolled 41
    |                O |   |    O           X |  
    |                O |   |                X |  
    |                O |   |                X |  
    |                  |BAR|                  |^ 2 point match (Cube: 1)
    |                X |   |                O |  
    |                X |   |                O |  
    |                X |   |    X           O |  
    | O              X |   |    X           O |  
    | O              X |   |    X           O |  0 points
    +24-23-22-21-20-19------18-17-16-15-14-13-+  X: Trailer

    1. Cubeful 2-ply    24/23 13/9                   MWC:  50.00%
       0.500 0.137 0.005 - 0.500 0.130 0.004
        2-ply cubeful 100% speed [world class]
    2. Cubeful 2-ply    24/23 24/20                  MWC:  50.00% ( +0.00%)
       0.498 0.122 0.005 - 0.502 0.129 0.004
        2-ply cubeful 100% speed [world class]
    3. Cubeful 2-ply    13/8                         MWC:  50.00% ( +0.00%)
       0.493 0.133 0.006 - 0.507 0.138 0.006
        2-ply cubeful 100% speed [world class]
    4. Cubeful 2-ply    24/20 6/5                    MWC:  50.00% ( +0.00%)
       0.488 0.122 0.005 - 0.512 0.139 0.005
        2-ply cubeful 100% speed [world class]

    GNU Backgammon  Position ID: 4HPwATDgc/ABMA
                    Match ID   : AQFGABAAAAAA
    +-1--2--3--4--5--6-------7--8--9-10-11-12-+  O: Leader (Cube: 2)
    | X              O |   |    O           X |  1 point
    | X              O |   |    O           X |  Rolled 41
    |                O |   |    O           X |  
    |                O |   |                X |  
    |                O |   |                X |  
    |                  |BAR|                  |^ 2 point match
    |                X |   |                O |  
    |                X |   |                O |  
    |                X |   |    X           O |  
    | O              X |   |    X           O |  
    | O              X |   |    X           O |  0 points
    +24-23-22-21-20-19------18-17-16-15-14-13-+  X: Trailer

    1. Cubeful 2-ply    24/23 13/9                   MWC:  50.03%
       0.500 0.137 0.005 - 0.500 0.130 0.004
        2-ply cubeful 100% speed [world class]
    2. Cubeful 2-ply    24/23 24/20                  MWC:  49.83% ( -0.20%)
       0.498 0.122 0.005 - 0.502 0.130 0.004
        2-ply cubeful 100% speed [world class]
    3. Cubeful 2-ply    13/8                         MWC:  49.36% ( -0.67%)
       0.494 0.131 0.005 - 0.506 0.135 0.005
        2-ply cubeful 100% speed [world class]

--Ian