Tuesday, February 17, 2015

[riczxmwy] Entire isotropic chess

A huge 26 by 26 chessboard with each player starting with 169 pieces, so the initial piece density is 0.50, same as orthodox chess (and incidentally almost the same as shogi 40/81). Initial position pawns separated by 4 ranks with 117 empty spaces among the back 10 ranks.

26 pawns, so 143 pieces behind the pawns.  Omitting the Dummy (or stone), use these 71 other uniform isotropic piece types, so two of each (142) plus one royal King moving the same as the two nonroyal Manns.  It's nice that the numbers work out so well. (Update: we probably want 8 alfils because they are thrice colorbound and 4 dabbabas and 4 dabbaba-alfil compounds because they are doubly colorbound. Are there any other multiply colorbound pieces in this set?)

Initial position of pieces (not pawns) is random like Chess960, with the constraint of evenly divided color bound pieces and all pawns initially protected.  King starts on back rank.  (If there are Dummies, then avoid completely trapped pieces.)

I slightly prefer the royal piece remaining the same as orthodox chess to preserve the endgame being a one square at a time chase.  But endgames might take forever.

Perhaps weaken the king further.  Wazir or Dummy (the Flag).

Alternatively shogi drops, so no endgames.  Possibly limitations on where drops can occur depending on who is attacking the destination square.

Dummies create more surfaces to trap the opponent's king.  (But also more places to hide.)  Perhaps captured pieces can be dropped as special Dummies which cannot be captured by opponent's king (but may by the opponent's other pieces).

(Or make the board larger with a considerable number of initial Dummies which never move?    A 28 by 28 board could have 27 dummies per player to achieve 50% initial piece density.  Perhaps feels like a minefield.)

Let the pawn be a wazir-ferz hybrid.  Allowing pawns to move backward lessens the need for castling and promotion.  Otherwise a pawn would have to travel a long way to promote.  Perhaps still permit 2 square initial forward move among the first 11 ranks (on a 26 board), as well as en passant capture, though this ruins isotropicity.

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