Extra pieces are the Coordinators which move like queens but capture in cooperation with the king. After a Coordinator move, any enemy piece positioned on the same rank as the friendly king, and on the same file as the Coordinator, or vice versa, is captured. The intersection points of the orthogonals are where capture occurs. The Coordinator can capture two pieces at once.
The Coordinator is stronger than a light piece, but weaker than a rook. In the endgame it could be as useful as a rook while it's easier for the king to be active. The Coordinator is strongest when the friendly king is close to the centre, while it loses much of its power when the king is in the corner. It is probably a good idea to let the king remain in the centre as long as possible.
The Coordinator seems to have just the right value to make the game strategically interesting. To realize a pawn majority in the endgame could be very difficult if the opponent still has recourse to a Coordinator. The Coordinator can effectively stop a pawn's advance from afar. This could be a drawback of this variant. On the other hand, the matter is often settled in the middlegame due to the many tactical possibilities.
Coordinator Chess was invented by George Dekle Sr, 1986. Please also see Correlator Chess, which uses a similar but more powerful piece.
The Coordinator can capture both bishops by going to the marked square.
Reference
The Classified Encyclopedia of Chess Variants, 2007.
• You can download my free Coordinator Chess program here (updated 2008-08-24), but you must own the software Zillions of Games to be able to run it (I recommend the download version).
• Don't miss my other chess variants.
© M. Winther (May 2007).