problem where one or both players are always required to make the long
est legal move on their turn. By "longest" we mean the move which involves moving a piece the longest distance; for example, Pythagorus' theorem
informs us that a knight
move is always root-5 units long (measured between the centres of the squares involved), and is therefore longer than a two-square pawn
advance. When castling, the sum of the distances moved by the king and rook is used (so queenside castling
counts as five units of length). If there is a tie for the longest legal move, the player may choose between the equally-longest moves available to him. The maximummer condition was invented by Thomas Dawson
As often happens when defining fairy conditions, check is a special case. One might think that, if Black is obliged to follow the longest-move rule, White is not really in check unless the capture of his king is Black's longest available move. However, to keep things in line with orthodox chess, it is usually stipulated that White is in check in all cases where his king is attacked by a Black piece.