Hexagonal Chess

Hexagonal Chess is a modification of the traditional game of chess, played on a hexagonal board. A board is defined as an n-board if the board has n hexagons on the bottom row of the board.  All boards we used for this game are regular hexagonal boards. This means that the board has the same number of hexagons on every side.  At right is an example of a 5-board.

What is the minimum number of bishops (knights, kings, queen, etc) can be placed on the board so that all sites are challenged (the board is dominated)?  What is the maximum number of bishops (knights, kings, queen, etc) that can be placed on the board so that no bishop is able to capture another (all are independent).