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Subject: Re: 480 Positions in Shuffle Chess

Author: Slobodan R. Stojanovic

Date: 16:45:21 07/07/03

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On July 07, 2003 at 19:40:47, Pierre Chevalier wrote:

Shuffle Chess and Fischer Random Chess are two different modalities.

SL.


>There are only 480 positions in Shuffle Chess also known as FischerRandom.
>The other half of the supposed 960 positions are mirror image errors.
>It is standardly accepted that the king moves two squares to castle.
>All shuffle chess positions can be represented with the king on c1, e1 or g1.
>All other arrangements are left-right reversals.
>When the king begins on c1 it castles to g1 or stays put.
>When the king begins on e1 as normal it castles to c1 or g1.
>When the king begins on g1 it castles to c1 or stays put.
>In all these cases the rook will wrap around the king as standard.
>The number 960 is the wrong number. To say there are 960 positions is to
>count mirror images as if they represented new positions.  Mirror image
>arrangements do not represent a new format; they represent a mistake in
>counting.  In this case mirror image means reversing the order along the back
>rank.
>Consider the position RNBKQBNR.  Is this a new position?  No.
>This is not a new position.
>The variant shuffle chess creates 479 new positions in addition to the
>standard chess position.



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