[Bug-gnubg] GnuBG faring poorly in back games

[Rod Roark]

Sorry if this reaches the list twice... the first send was
with a different sender address than my subscription.

ParlorBot is a bot on FIBS that uses a recent build of GnuBG.
It seems that some players have figured out how to do pretty
well against it, by deliberately playing severe back games.

Is this a known problem?  Following are a couple of sample
games in Jellyfish format:

 15 point match

 Game 1
 parlorbot : 0                 logistics : 0
  1)                            51: 8/3 6/5
  2) 23: 24/22* 24/21           31: 25/22 8/7
  3) 55: 22/17* 13/8 8/3* 8/3   12: 25/24 25/23
  4)  Doubles => 2               Takes
  5) 24: 8/4 6/4                 Doubles => 4
  6)  Takes                     61: 24/23 13/7
  7) 14: 21/20* 17/13           54: 25/20 20/16
  8) 42: 13/9* 9/7              42: 25/23 13/9
  9) 46: 20/16* 16/10           55: 25/20 13/8 13/8 13/8
 10) 14: 13/9 6/5*              33:
 11)  Doubles => 8               Takes
 12) 56: 13/7 10/5               Doubles => 16
 13)  Takes                     56:
 14) 32: 13/10 13/11            32: 25/23 8/5
 15) 45: 11/7 10/5              64: 23/17* 17/13
 16) 36: 25/22 22/16            56: 23/17 13/8
 17) 53: 16/11 11/8*            34:
 18) 13: 8/7 7/4                25: 25/23 8/3
 19) 23: 9/7 7/4                31: 7/4 6/5
 20) 55:                        51: 8/3 6/5
 21) 33: 7/4 7/4 7/4 6/3        45: 23/18 8/4
 22) 53: 5/0 3/0                33: 18/15 15/12 12/9 5/2
 23) 45: 5/0 4/0                35: 23/20* 7/2
 24) 33:                        12: 20/18 18/17
 25) 12: 25/24 4/2*             44:
 26) 15: 4/3                    43:
 27) 32: 6/3 4/2                35: 25/20 9/6
 28) 25: 6/4                    16: 20/19 19/13
 29) 64: 24/18 18/14            62: 17/11* 11/9
 30) 33:                        65: 24/18 18/13
 31) 21: 25/24 4/2              22: 13/11 11/9 9/7 9/7
 32) 33: 4/1* 4/1 4/1           43: 25/21 21/18
 33) 43:                        46: 18/14 14/8
 34) 14: 3/2                    66: 13/7 8/2 7/1* 7/1
 35) 42:                        64: 7/3 6/0
 36) 24:                        64: 6/0 6/2
 37) 23:                        13: 3/0 2/1
 38) 54:                        24: 4/2 4/0
 39) 12:                        22: 5/3 5/3 2/0 2/0
 40) 66: 25/19 19/13 13/7 7/1   11: 2/1 1/0 1/0 1/0
 41) 35: 3/0 3/0                61: 3/0 1/0
 42) 33: 3/0 2/0 2/0 2/0        56: 3/0 3/0
 43) 13: 2/1 1/0                51: 3/0 2/1
 44) 45: 1/0 1/0
                                 Wins 16 points

 Game 2
 parlorbot : 0                 logistics : 0
  1) 25: 24/22 13/8             52: 8/3* 6/4
  2) 36: 25/22* 22/16           11: 25/24 24/23 23/22 6/5
  3) 46: 24/20* 16/10           44: 25/21 13/9 13/9 9/5*
  4) 56: 25/20* 10/4*           63: 25/22
  5) 21: 8/7 6/4                32: 25/22 22/20
  6) 62: 20/14 7/5*             36: 25/22 22/16
  7) 51: 14/9* 6/5              35: 25/22 13/8
  8)  Doubles => 2               Takes
  9) 31: 13/10 10/9              Doubles => 4
 10)  Takes                     46: 13/9 13/7
 11) 22: 13/11 11/9 9/7 9/7     46: 22/16* 8/4
 12)  Doubles => 8               Takes
 13) 35: 25/20 8/5              26: 16/10 7/5*
 14) 55: 25/20* 20/15* 15/10 7/2  Doubles => 16
 15)  Takes                     32: 25/22 25/23*
 16) 24: 25/23 6/2*             15: 25/24 8/3
 17) 54: 23/18 18/14            44: 22/18* 22/18 9/5 9/5
 18) 15: 25/24 10/5             64: 24/18 22/18
 19) 31: 24/23 5/2              44: 18/14 18/14 8/4 6/2*
 20) 66:                        36: 14/11* 11/5
 21) 56:                        35: 14/9 5/2
 22) 36: 25/22*                 44:
 23) 15: 25/24 22/17            42:
 24) 54: 17/12 12/8             14: 25/24 9/5
 25) 44: 13/9 13/9 9/5 9/5      35: 18/15 18/13
 26) 54: 8/3 8/4                65: 24/18 18/13
 27) 66: 24/18 8/2              64: 15/11 13/7*
 28) 53: 25/22 22/17            64: 11/5 7/3
 29) 55: 17/12* 12/7 7/2 5/0    12: 25/24 24/22*
 30) 62:                        63: 22/16 16/13
 31) 33: 25/22* 6/3 6/3 5/2     26: 25/19 5/3*
 32) 51: 25/24                  54: 19/14 5/1*
 33) 66:                        66: 24/18 14/8 13/7 7/1
 34) 42:                        44: 18/14 14/10 10/6 8/4
 35) 25:                        51: 24/19 4/3
 36) 63:                        26: 19/17 17/11
 37) 24:                        32: 11/8 8/6
 38) 44:                        43: 6/2 6/3
 39) 36:                        26: 6/4 6/0
 40) 62: 25/19 19/17            55: 5/0 5/0 4/0 4/0
 41) 21: 17/15 2/1
                                 Wins 16 points

GnuBG is run in TTY mode and is initialized as follows:

To gnubg: set player 1 name opp
To gnubg: set confirm new off
To gnubg: set display off
To gnubg: set output rawboard on
To gnubg: set evaluation chequer eval plies 2
To gnubg: set evaluation chequer eval cubeful on
To gnubg: set evaluation cubedecision eval plies 2
To gnubg: set evaluation cubedecision eval cubeful on
To gnubg: set analysis chequer eval plies 2
To gnubg: set analysis chequer eval cubeful on
To gnubg: set analysis cubedecision eval plies 2
To gnubg: set analysis cubedecision eval cubeful on

Any thoughts?

-- Rod