A Game Courier Preset for Yapsan's Spherical Chess
Click here to view, print, or download the north hemisphere image.
Click here to view, print, or download the south hemisphere image.
Rules enforced. Legal moves displayed.
Yapsan's Spherical Chess is an adaptation of Chess to a spherical board. As in Cylindrical Chess, the ranks loop back into themselves, allowing movement to continue from one side to the other. Besides that, pieces may move over the poles. Apart from changes made to piece movement to accomodate a spherical board, this is played by the same rules as Chess.
The rook may continue its move directly over a pole by going to the space in the same rank on the other side, which will be four files away, and then reverses its vertical direction.
A Bishop also continues its move by crossing the pole to the space four files away. This keeps it colorbound, since opposite spaces around a pole are the same color. It then reverses both its directions, which puts it on a non-intersecting loop with its original space.
The Queen moves as a Rook or a Bishop.
The King moves one space as a Queen. This gives it only six moves when it's by a pole. Besides regular castling, it may castle with a Rook by moving towards it in the opposite direction it would have to go to castle with it in Chess. This is allowed only when the Rook it would normally castle with by moving in that direction has moved away, and all other usual conditions for castling apply.
The Knight leaps to any space that may be reached by the combination of one Rook move in one direction and two more in a perpendicular direction. Besides the usual spaces it may reach in Cylindrical Chess, it may cross the pole. A Knight next to a pole has four trans-polar moves. After going across the pole to the space in the same rank on the other side, two moves go two more spaces east or west. This is equivalent to the Knight leaping two spaces horizontally. Another two go two spaces over the pole and one more space east or west. From the second rank from a pole, a Knight can cross the pole and then turn one space east or west. These additional moves give it eight possible moves from any space on the board.
The Pawn can never cross the pole, because it must promote upon reaching the last rank. So, it moves as it does in Cylindrical Chess. It's like a regular Chess Pawn whose movement can cross the a/h divide when capturing diagonally.
When a Bishop, Rook, or Queen is able to make a complete loop and return to its original position, it is allowed to do so. Yapsan calls this a stationary or infinite move. Note that you cannot make such a move by clicking or tapping the board. You will have to enter it in the Moves field.
Turning the Hemispheres
When you make a move or view your opponent's move, the two hemispheres will align along ha, bc, de, or fg, depending on which file the move was to. Before making your move, you can rotate the two hemispheres to any file or border between files that you want paired up on each board. Select a different meeting point in the Customize Appearance section, and click on Move or Preview without entering a move.
How to Move Pieces
Full Algebraic Notation
Algebraic notation identifies each space by a coordinate that begins with its file label and ends with its rank label. On the Chess board, files go up and down from one player to the other, and ranks go from left to right. In most games, files are represented by letters, and ranks are represented by numbers, but there is no fixed rule requiring this for all games, and some games, such as Shogi, reverse this convention. If you look at the diagram, you will usually see the file labels going from left to right and the file labels going up and down. And if you hover your mouse over a space, you will normally see the name of the coordinate appear in a tooltip.
It is not uncommon to see algebraic notation being used for Chess, but it is often in an abbreviated format that requires you to know both the rules of the game and the current position to know exactly which piece moves where. For example, the notation "Ne6" indicates that a Knight is moving to e6, but it doesn't indicate which Knight, and it doesn't specify where the Knight is coming from. To figure this out, you need to know how a Knight moves and which Knight on the board can make a legal move to e6.
Although rules may be programmed for individual games, Game Courier itself does not know the rules of any game, and it is unable to parse abbreviated algebraic notation. Therefore, it relies on full algebraic notation, which completely specifies the move without requiring any knowledge of the game's rules or the current position. The most usual type of full algebraic notation indicates the piece that is moving by its label, the space it is moving from, and the space it moving to. In Chess, a typical first move might be written as "P e2-e4". When you hover your mouse over a piece, you will normally see the piece label followed by the coordinate for the space, and when you hover it over an empty space, you will normally see the coordinate label. Including the piece label in your notation allows Game Courier to check that the piece you're moving is the right one, and it makes game notation easier to follow, but it is not mandatory.
You may promote a piece by including a promotion move after your regular move. A promotion move has a piece go directly to a coordinate. Here is an example: "p e7-e8; q-e8".
You may remove a piece from a space by adding an @ to the space or by omitting the destination coordinate. For example, both "@-e4" and "e4-" would remove the piece on "e4". This is useful for en passant when you are playing a game that does not handle this automatically. For example, "P d5-e6; e5-" removes the Pawn on e5 after a Pawn moves from d5 to e6.
You will not need to remove spaces for most games, but if you should need to, you can do this by omitting the first coordinate in a move. For example, "-e4" would remove e4 from the board. To add or return a space to the board, you may add an @ or any other piece to it.
Available Pieces
Pieces are represented by labels, usually using uppercase letters for White and lowercase letter for Black. When you enter a move or specify the starting position for a game, you should remember that piece labels are case-sensitive. Many piece sets are available for use with Game Courier, and this table shows you which pieces belong to the piece set you are currently using.
The inclusion of a piece does not indicate that it is used in the game you are playing. But if your game uses pieces not included here, you should choose a different piece set.
Credits
This preset uses the default settings file for Yapsan's Spherical Chess, which was made by Fergus Duniho.
Game Courier was created, programmed and written by Fergus Duniho.
Game Courier, Copyright © Fergus Duniho, 2001-2017
WWW Page Created: 15 August 2001