The "Indirect Defense" is a chess tactic that involves defending a piece or pawn by placing another piece or pawn in the attacking line, rather than moving the attacked piece or pawn directly. This tactic can be used to protect a valuable piece or pawn, to lure the opponent's attacking pieces away from a more important area, or to create a counter-attack opportunity.
The Indirect Defense can be found in many openings and it can be used with any type of piece. A common example of Indirect Defense is the move Nd2 in the Sicilian Defense, which protects the e4 pawn and prepare d3 to free the c1 bishop. Another common example is Rf1 in the Ruy Lopez, which protects the e1-rook, and prepares the f3 move to free the e1-bishop.
The Indirect Defense is considered a subtle and versatile tactic that can be used in different stages of the game. It can be used to protect a weak pawn, to cover a vulnerable square or to create a counter-attack opportunity. It can also be used in coordination with other tactics such as pins and forks.
To prevent the Indirect Defense, players should be aware of the potential threats that their opponent can make and try to anticipate the opponent's moves. They should also try to keep their pieces active and try to control the key squares on the board.