Interference (chess) Interference (chess) In the game of chess, interference occurs when the line between an attacked piece and its defender is interrupted by sacrificially interposing a piece. It is a chess tactic which seldom arises, and is therefore often overlooked. Opportunities for interference are rare because the defended object must be more valuable than the sacrificed piece, and the interposition must itself represent a threat. In the position at left, White to play will apparently be obliged to retreat the knight from f5, because the squares to which it could advance are all guarded. However, the interference move 1.Nd6+ interrupts the
Fairy chess piece David Parlett used a notation to describe fairy piece movements. The move is specified in the form m={"expression"}, where "m" stands for "move", and the "expression" is composed from the following elements: The following can be added to Parlett's to make it more complete: The format (not including grouping) is: <conditions> <move type> <distance> <direction> <other> On this basis, the traditional chess moves (excluding castling and "en passant" capture) are: Ralph Betza created a classification scheme for fairy chess pieces (including standard chess pieces) in terms of the moves of basic pieces with modifiers. Capital letters stand for basic leap