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Chess480. Missing description (8x8, Cells: 64) [All Comments] [Add Comment or Rating]
Gene Milener wrote on 2006-02-18 UTC
Chess players interested in ches480 or chess960 (a.k.a. Fischer Random
Chess, FRC) may be interested to hear that a major new chess960 book has
been published (Jan 2006).  Title is:

'Play Stronger Chess by Examining Chess960:
Usable Strategies of Fischer Random Chess Discovered'

(ISBN 0-9774521-0-7)

Searching in or will find the book.

Or visit

I suspect that chess480, with its castling rule having the King move two
squares instead of to the traditional squares c1 or g1, would lead to
OPPOSITE WING castling games than would chess960/FRC.
Thus I suspect the draw rate would be higher in chess480 than in
Generally a higher draw rate is bad.

In my chess960 book I describe a tweak of the chess960 castling rule,
designed to increase the rate of opposite wing castling.  Statistics show
that the draw rate is lower when the two players castle to opposite
 Opposite wing castling is almost rare in traditional 'chess1', which
be considered a flaw in the engineering of the rules (choices made when
chess1 was invented in the 1400's).  Basically, my rule would give the
second player to castle more freedom to choose the destination square of
his castling king, if but only if he castles to the opposite wing.

Thank you.
Gene Milener

Reinhard Scharnagl wrote on 2006-02-12 UTC
I am just about to implement Chess480 in my SMIRF program. SMIRF will then randomly select positions from Chess960, but only those, where the white king is right sided to the queen. Thus the redundant half of mirrored starting arrays is filtered out. To distinguish its FEN, a preceding 'm' is placed immediately before the castling tags block, as specified in current X-FEN.

John Lewis wrote on 2005-10-19 UTC
I'd prefer to continue to use both branches, as variety is part of the goal in this type of variant. Being human we may see something in one version that we might miss in it's reflection.

Austin Lockwood wrote on 2005-10-19 UTC
Reinhard, we have used your numbering scheme to identify Chess480 starting
arrays (since these are identical to Chess960 positions) - I hope this is
OK with you?


Thomas McElmurry wrote on 2005-10-19 UTC
Regarding the questions about which 480 positions should be used:

Rather than thinking of 2 sets of 480 positions, perhaps it's better to think of 480 sets of 2 positions. The two positions in each set are related by left-right reflection, and have equivalent strategy trees.

I agree with John that it's aesthetically preferable to play all 960 positions, but if you want to choose just one from each pair, how about the one where the Queen is to the left of the King in White's starting position?

Roberto Lavieri wrote on 2005-10-18 UTC
CHESS960 top ratings:

   1     Svidler,Peter                      2755
   2     Aronian,Levon                      2752
   3     Bacrot,Etienne                     2746
   4     Leko,Peter                         2735
   5     Adams,Michael                      2735
   6     Shirov,Alexey                      2723
   7     Morozevich,Alexander               2719
   8     Ponomariov,Ruslan                  2716
   9     Dreev,Alexey                       2711
  10     Sokolov,Ivan                       2687
  11     Grischuk,Alexander                 2682
  12     Kobalija,Mihail                    2679
  13     Almasi,Zoltan                      2676
  14     Jussupow,Artur                     2670
  15     Zvjaginsev,Vadim                   2670
  16     Rublevsky,Sergei                   2667
  17     Landa,Konstantin                   2660
  18     Motylev,Alexander                  2657
  19     Sasikiran,Krishnan                 2656
  20     Nielsen,Peter-Heine                2652
  21     Bologan,Victor                     2650
  22     McShane,Luke-James                 2645
  23     Gurevich,Mikhail                   2643
  24     Sargissian,Gabriel                 2635
  25     Milov,Vadim                        2632
  26     Harikrishna,Pentela                2628
  27     Nisipeanu,Liviu-Dieter             2626
  28     Gyimesi,Zoltan                     2625
  29     Vallejo Pons,Francisco             2624
  30     Sutovsky,Emil                      2622

Reinhard Scharnagl wrote on 2005-10-11 UTC
There is of course a numbering scheme for Chess960 (Fischer Random Chess).
I invented it some years ago, and it is widely accepted. For details see
e.g. in my (German) book on Chess960 or see at the two page
document I gave (first page with table) to the Chess Tigers .

With best regards, Reinhard Scharnagl.

Christine Bagley-Jones wrote on 2005-10-10 UTC

Roberto Lavieri wrote on 2005-10-10 UTC
Is still Peter Svidler the World Chess960 champion?

Christine Bagley-Jones wrote on 2005-10-09 UTC
how come they didn't like to use fischer name ... bit weird .. fischer himself says that only a certain number of the positions should be used, and it isn't that many, under 20 i think i remember him saying .. so their name is stupid i reckon, if it ever become the standard chess for the world, which i highly doubt, the inventor thinks most of the start positions should not be used.

John Lewis wrote on 2005-10-09 UTC
Sorry Greg, but that is only one of *several* numbering systems I've seen.
 What I said was that there was no *standard* number system I was aware

To show a mirror position in order to explain why there are technically
only 480 positions if Orthodox Castling is used.

The term 'Chess960' was invent by Hans-Walter Schmitt (chairman of the
Frankfurt Chess Tigers e.V.) after debate over a new name that did not
include Bobby Fischer's name.

Greg Strong wrote on 2005-10-09 UTC

There is most certainly a set numbering system for identifying Fischer Random Chess positions. See:

While I'm on the subject, does anyone know where the name Chess960 came from? This game was invented by Bobby Fischer; has he accepted or acknowledged this new name?

John Lewis wrote on 2005-10-08 UTCExcellent ★★★★★
Because there is no standard numbering system for Fischer Random Chess (Chess960), it would be hard for me to make a rule to explain which are duplicates due to being mirrors. It's likely that any system for generating all 960 positions would probably start mirroring at 480... so 480 and 481 would likely be mirrored positions.

Anonymous wrote on 2005-10-05 UTCExcellent ★★★★★
What distinguishes one set of 480 positions from the other set of 480 positions?

John Lewis wrote on 2005-10-02 UTCExcellent ★★★★★
Both sets of 480 are played for aesthetic reasons.

Anonymous wrote on 2005-10-01 UTCExcellent ★★★★★
Which half of the 960 positions of Fischerandom are used in Chess480? The article does not specify which one of a mirrored pair is played in Chess480.

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