Queenfest VI: Peaceful Coexistence By Jeff Coakley Queenfest returns once again. As usual, the puzzles involve multiple queens. The task is to arrange the queens on the board to achieve certain goals. The first puzzle is an example of independent domination. “Independent” because the queens do not protect each other. “Domination” because all vacant squares are under their control. Queenfest #19 (six queens) [FEN "8/8/8/8/8/8/8/8"] Place six queens on the board so that no queen is defended and every empty square is attacked. Earlier Queenfest columns are in the archives. Harem Scarum. The next puzzle uses an equal number of white and black queens. Parts A and B were first … [Read more...]

Queenfest V: Harem Scarum By Jeff Coakley Queenfest rolls on with more puzzles involving multiple queens. The task is to arrange the queens on the board to achieve certain goals. The first part of the first puzzle is very easy, but figuring out the number of possible solutions is perhaps an interesting challenge. Queenfest #16 (four queens) [FEN “8/8/8/8/8/8/8/8”] Place four queens on the board so that each queen is defended by every other queen. How many solutions are there? Earlier Queenfests can be found in the archives: A Royal Heyday, Second to None, We Will Rock You, Breaking Free. The next puzzle explores the lower limits of queen mobility. Except for 17a, all … [Read more...]