Robertie Position 101

This is a very interesting position in which the GNU 0-ply evaluation of 13/8 13/7 is so far below that of 13/8 10/4 that it does not even make it through the move filter (unless the move filter is set to be extremely large). Even GNU 4-ply thinks that 13/8 13/7 is clearly worse (by 0.033 equity) than 13/8 10/4.

Bob Koca points out that 13/8 13/7 is an example of a cube provocation play. That is, after Black plays 13/8 13/7, White has a clear double, while if Black plays 13/8 10/4, White does not have a double. Nevertheless, 13/8 13/7 is the preferred play.

# Ply Move Equity
• 1 R 13/8 13/7 -0.346
 
0.4230.1030.005-0.5770.2730.034 -0.353 -0.346
0.0010.0010.000-0.0010.0010.001 0.003 0.009
  
  Full cubeful rollout with var.redn.  
  5184 games, Mersenne Twister dice gen. with seed 842665845 and quasi-random dice  
  Play: supremo 2-ply cubeful prune [world class]  
  keep the first 0 0-ply moves and up to 16 more moves within equity 0.32  
  Skip pruning for 1-ply moves.  
  Cube: 2-ply cubeful prune [world class]  
  2 R 13/8 10/4 -0.417 ( -0.071)
 
0.3990.1220.005-0.6010.2160.018 -0.309 -0.417
0.0010.0010.000-0.0010.0010.000 0.002 0.006
  
  Full cubeful rollout with var.redn.  
  5184 games, Mersenne Twister dice gen. with seed 842665845 and quasi-random dice  
  Play: supremo 2-ply cubeful prune [world class]  
  keep the first 0 0-ply moves and up to 16 more moves within equity 0.32  
  Skip pruning for 1-ply moves.  
  Cube: 2-ply cubeful prune [world class]  
  3 R 24/13 -0.859 ( -0.513)
 
0.3590.0900.004-0.6410.3780.010 -0.577 -0.859
0.0020.0010.000-0.0020.0030.001 0.005 0.014
  
  Full cubeful rollout with var.redn.  
  1296 games, Mersenne Twister dice gen. with seed 870006691 and quasi-random dice  
  Play: supremo 2-ply cubeful prune [world class]  
  keep the first 0 0-ply moves and up to 16 more moves within equity 0.32  
  Skip pruning for 1-ply moves.  
  Cube: 2-ply cubeful prune [world class]