[Retros] series SPG

[Goran Wicklund]

> From: Richard Stanley <rstan at math.mit.edu>

> To: retros at janko.at

> Date: Thu, 2 May 2002 11:22:12 -0400 (EDT)

> 

> 

> Here is a variation of Noam Elkies' request for a dual-free SPG in

> which every unit moves. Remove all Black units from the board. What is

> the maximum number of White units that can move in a dual-free series

> SPG? I can do 14 (if sound), but presumably that can be improved. The

> same question can be asked without first removing the Black units.

> 

> Richard

> 


Here is try to move 15 white units. It should also work with the
black units on board: 

8/6Q1/5B2/R3RBN1/P3PP1K/1P1P2PP/2P5/N7
+---+---+---+---+---+---+---+---+

|   | . |   | . |   | . |   | . |

+---+---+---+---+---+---+---+---+

| . |   | . |   | . |   | Q |   |

+---+---+---+---+---+---+---+---+

|   | . |   | . |   | B |   | . |

+---+---+---+---+---+---+---+---+

| R |   | . |   | R | B | N |   |

+---+---+---+---+---+---+---+---+

| P | . |   | . | P | P |   | K |

+---+---+---+---+---+---+---+---+

| . | P | . | P | . |   | P | P |

+---+---+---+---+---+---+---+---+

|   | . | P | . |   | . |   | . |

+---+---+---+---+---+---+---+---+

| N |   | . |   | . |   | . |   |

+---+---+---+---+---+---+---+---+
 16 + 0  SPG 28  No black units on board
 
 
 Göran Wicklund