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Fischer Random Chess

Bobby Fischer, a former world chess champion, proposed a variant of Orthodox Chess wherein the initial setup of pieces is chosen randomly. Fischer thereby joined the ranks of other former world champions, such as Capablanca, who proposed changes to the rules of chess -- none of which were ever implemented. Fischer Random Chess is somewhat similar to the older Shuffle Chess, or Prechess (or other related variants), yet has a unique style of its own. An extensive introduction and history of the game was written by Eric van Reem.

Setup

Fischer Random Chess is played with an Orthodox Chess set but employs a randomly generated array. Each new setup is determined by a computer program (or manual procedure) which assigns starting squares according to the following guidelines:

The Interactive Diagram below will shuffle the pieces when you click Restart in the Play It! panel. You may select from some different piece sets by clicking one of the buttons above the board.

graphicsDir=/play/pbm/showpiece.php?size=50%26set=magnetic%26piece= graphicsType=png whitePrefix=W blackPrefix=B squareSize=50 lightShade=#EEEECC darkShade=#226822 symmetry=mirror shuffle=N!BRQK pawn:::P:a2-h2 knight:N::N:b1,g1 bishop:::B:c1,f1 rook:::R:a1,h1 queen::Q:Q:d1 king:::K:e1

Pieces

Orthodox Chess pieces are used exclusively.

Rules

Orthodox Chess rules apply when applicable.

Castling may be performed under the following conditions:

A King may castle with its a-side Rook or its h-side Rook. When castling a-side, the King and Rook go to the same spaces they would go when Queen-side castling in Chess. When castling h-side, the King and Rook go to the same spaces they would go when King-side castling in Chess. This table shows where the King and Rook end up for each type of castling.

White castles a-sideKc1, Rd1
White castles h-sideKg1, Rf1
Black castles a-sideKc8, Rd8
Black castles h-sideKg8, Rf8

More detailed rules may read in an archived copy of a page from Bobby Fischer's website before his death:

Computer Play

If you have Zillions of Games installed on your computer, you can play this game. Download file: fischer.zip.

Number of Possible Arrays

Terumi Kaneyasu (Sam Sloan?) writes:

Fischer Random Chess has 960 legal arrays. This number is determined as follows:

First, place the two Bishops. There are 16 different ways for one bishop to be on a white square and the other Bishop to be on a black square.

That leaves six empty squares. Now, place the King somewhere between the two Rooks. There are 20 different ways for a King and two Rooks to occupy six squares with the King in between.

That leaves three squares for the two Knights and the Queen. There are three possible ways to place these pieces.

Thus, there are 16 x 20 x 3 (960) legal arrays in Fischer Random Chess.

See Also:


Written by various authors. Information based on news postings by Terumi Kaneyasu; send to me by Terumi Kaneyasu and Dennis Breuker. Modest Solans noticed an error in an earlier version. The picture of Fischer is from Palle Mathiasen's World Chess Champions site. Edited by John William Brown for the occasion of this variant being selected Recognized Variant of the Month for April 2002. Rules corrected by Fergus Duniho in May, 2004.
WWW page created: 1995 or 1996.