Balbo's chess

This game, invented by M. G. Balbo in 1974, is mentioned in Pritchard's Encyclopedia of Chess Variants.

Board and rules

The board of this game has an unusual shape. Each rank is centered around the f file, and the width of each rank is, consecutively, three, five, seven, nine, eleven, eleven, nine, seven, five, and three spaces. The board and opening setup is as follows.

Pawns promote as usual on the tenth rank, or on the last space on the d or h files. These are d9 and h9 for White, d2 and h2 for Black. On the last spaces on the c and i files, a Pawn may promote to a minor piece, i.e. to a Knight or Bishop. These are c8 and i8 for White, c3 and i3 for Black. The rules on this page originally included Rook, but the description in Pritchard's book just says minor piece. In Chess, the minor pieces are the Knight and the Bishop. Although Pritchard says, "Bishops are as powerful as rooks," this does not appear to be true. Even with the board changed, it appears that the King+Rook combination can checkmate a lone King, but the King+Bishop combination cannot. So, unless we can get another source on this game than Pritchard, it should be assumed that Pawns can only promote to Knights or Bishops on the c and i files.

Pritchard warns that against stupid play, each player has Nxf3/8 mate on the third move.

Note: The diagram in Pritchard's book has the colors of the spaces reversed. This does not affect gameplay, and I changed it from how it looks in Pritchard, because it creates better contrast between board and pieces to have more dark squares on White's side and more light squares on Black's side. -- Fergus

The diagram here uses the 'magnetic' piece images.

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