Janus Chess is a chess variant invented in 1978 by Werner Schöndorf[1] from Bildstock, Germany. It is played on a 10×8 board and features a fairy chess piece, the janus, with the combined moves of a bishop and a knight. The janus piece is named after the Roman god Janus because this god was usually depicted with two faces looking in opposite directions.

abcdefghij
8a8 black rookb8 black princessc8 black knightd8 black bishope8 black kingf8 black queeng8 black bishoph8 black knighti8 black princessj8 black rook8
7a7 black pawnb7 black pawnc7 black pawnd7 black pawne7 black pawnf7 black pawng7 black pawnh7 black pawni7 black pawnj7 black pawn7
6a6b6c6d6e6f6g6h6i6j66
5a5b5c5d5e5f5g5h5i5j55
4a4b4c4d4e4f4g4h4i4j44
3a3b3c3d3e3f3g3h3i3j33
2a2 white pawnb2 white pawnc2 white pawnd2 white pawne2 white pawnf2 white pawng2 white pawnh2 white pawni2 white pawnj2 white pawn2
1a1 white rookb1 white princessc1 white knightd1 white bishope1 white kingf1 white queeng1 white bishoph1 white knighti1 white princessj1 white rook1
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Janus Chess initial position. The januses (knight+bishop compounds) start on the b- and i-files.

Description

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The usual set of chess pieces is extended with two pawns and two januses per player. Each janus is placed between a rook and a knight. The relative position of the king and queen is reversed compared to chess. After castling, the king stands on either the b- or i-file and a rook stands on either the c- or h-file, depending on which side castling is done.

The janus is considered almost as powerful as a queen and is usually valued at about 8 points (based on chess piece values with pawns valued at 1). It is the only piece in the game that is able to checkmate the opponent's king without the assistance of any other piece, with the king in a corner and the janus two squares away on a diagonal, but this checkmate cannot be forced. Due to the extra pieces, each player starts the game with considerably more "material power" compared to standard chess; however, the game has only a slightly higher material "power density",[2] since there is more room for players to maneuver pieces because of the larger board (10×8 = 80 squares). Due to the different board and pieces, players are unable to use normal chess opening theory, and chess tablebases have limited value in the endgame.

Janus Chess has been popular in Europe[3] with regular tournaments drawing strong players.[1] Several chess grandmasters have played this game including Viktor Korchnoi, Péter Lékó and Artur Yusupov. Korchnoi said: "I like playing Janus Chess because one can show more creativity than in normal chess."[1]

See also

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Chess engines that play Janus Chess:

References

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  1. ^ a b c Pritchard, D. B. (2007). "Janus Chess". In Beasley, John (ed.). The Classified Encyclopedia of Chess Variants. John Beasley. p. 124. ISBN 978-0-9555168-0-1.
  2. ^ vickalan (Jan 22, 2017). "Comparison of Material Power in Variant-Chess Games", Chess.com.
  3. ^ Game rules (Janus Chess), BrainKing.com.
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