by Graeme C. Neatham
IntroductionThe creation of A9 HexaChess was inspired by Derick Peterson's Grand Hexachess and by Dave McCooey's remark about his own Hexagonal variant:
"Our goal was to create the closest hexagonal equivalent to the real game of chess as possible"
Thus A9 HexaChess is my attempt at devising
"the closest hexagonal equivalent to the square-based variants of Grand Chess as possible"
SetupThe board consists of 169 hexes in three differing colours. The initial array is as illustrated here:
Pieces and RulesThe two sides are Gold and Red, Gold moving first. The pieces and their movement are generally as detailed in Derick Peterson's Grand Hexachess
|Pawn||Moves by advancing 1 rank along either file. Captures by advancing 1 rank along either diagonal. Has the option when moving, but not when capturing, of advancing two ranks along the same file provided it starts from within its own part of the board. May capture "en passant"
Promotion is optional on reaching the second and third far most ranks, but only to a captured piece. Pawns must promote on reaching the last rank when the choice is not restricted to captures.
|Bishop||Moves along diagonals||3|
|Knight||Moves 1 hex diagonally followed by 1 hex orthogonally, continuing in the same general direction||3|
|Guard||Referred to as a Duke by Derick Peterson. Combination of King and Knight
|Rook||Moves orthogonally, along ranks and files
|Templar||Referred to as a Vizir by Derick Peterson. Combination of Bishop and Knight
|Queen||Equivalent to the orthodox queen - combination of Rook and Bishop||1|
|Champion||Referred to as a War Machine by Derick Peterson. Combination of Rook and Knight
||Moves 1 hex in any direction. Castling is permitted||1|
NotesThe original working title for this variant was Imperial Grand HexaChess. I decided this was both too long and too similar to existing variants so chose the name A9 HexaChess, A9 being hexadecimal for 169, the number of hexes on the board. The colours of Red and Gold were chosen, while still using the working title, as being more Imperial than Black and White.
Relative Piece Values
Safe Check Value3
- Piece value in whole pawns, based upon the calculations and considerations presented here.
- Underlying values calculated using the method detailed
The actual formula applied was (d + c(1+1/6)/n, where d is sum of affected directions, c is sum of affected cells, and n is the number of cells.
- This method undervalues the Guard and overvalues pieces that use unlimited diagonal or orthogonal moves, since no allowance is made for the possibility of blocking pieces. Comparisons with calculations allowing for a blocking piece indicate that the overvaluation in relative terms is by 1 Pawn for diagonal movement and by 3 Pawns for orthogonal movement.
- The relative values have been standardized against the Knight's value which has been set as worth 3 Pawns.
- The King is, of course, invaluable.