Circular chess of the board and a different starting setup. In the citadel game, if a king reaches the citadel, a draw is forced. The starting position is essentially obtained from that of orthodox chess by cutting the board in half and bending the two halves to join at the ends. Two lines are marked on opposite sides of the board, and each set of pieces is positioned so as to straddle this line. The king and queen start on the innermost ring, with, as is the case in square chess, the queen on a square of the same colour; the bishops
Opposite-colored bishops endgame Paulsen and Adolf Anderssen in their unofficial world championship match. It was a draw because of the wrong rook pawn. Play continued: This 1620 game between an unknown player and Gioachino Greco was won by Black on move 50. Opposite-colored bishops endgame The opposite-colored bishops endgame is a chess endgame in which each side has a single bishop, but the bishops reside on opposite-colored squares on the chessboard, thus cannot attack or block each other. Without other pieces (but with pawns) these endings are notorious for their tendency to result in a draw. These are the most difficult endings in