A00-A99

A collection of miscellaneous responses to 1. d4. These lines are often used to avoid main-line theory or to transpose into other specialized systems.

A flexible defense that can lead to the King's Indian or Modern Defense. It focuses on controlling the center with pieces before deciding on a pawn structure.

A robust setup for White against the Modern Defense. White seizes a large central space and challenges Black to find counterplay on the flanks.

An old-school approach where Black challenges the center with c5. It creates unbalanced positions with a space advantage for White and activity for Black.

Black locks the center early, leading to a game of maneuvering. Success depends on managing the pawn breaks on either the f-file or the b-file.

Covers various aggressive White setups after 1. d4 Nf6. White often uses the Trompowsky or Richter-Veresov to take Black out of their comfort zone.

A standard positional approach where White avoids committing to c4 early. It is a very solid way to play 1. d4, focusing on harmonious development.

A prophylactic setup against the Nimzo-Indian. White develops the kingside first to deny Black the opportunity to pin the knight on c3.

White uses the London or Torre systems against the King's Indian. These setups are very safe and focus on a stable center and piece coordination.

A fianchetto system for White that avoids the main-line Samisch or Classical structures. It leads to quieter, more positional games.