Flank openings

London System

1.d4 Nf6 2.Nf3 g6 3.Bf4

The London System starts with 1.d4 Nf6 2.Nf3 g6 3.Bf4 and is catalogued under ECO A48, in the flank openings half of the book. The catalog indexes 4 lines inside it, grouped into 2 named variations.

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Current setup

Move ideas

  1. 1.d4

    Takes central space with a protected pawn and frees the queen’s bishop.

    Idea: Build a stable center that supports a broad positional setup.

  2. 1Nf6

    Develops a knight and prevents White from occupying e4 unchallenged.

    Idea: Keep the central pawns flexible and choose an Indian setup after White commits.

  3. 2.Nf3

    Develops the knight to f3, bringing it into the game.

    Idea: Improve piece coordination and clear the back rank for castling and the rooks.

  4. 2d5

    Advances to d5 to claim central space and control nearby key squares.

    Idea: Give the pieces room to develop behind a durable central foothold.

  5. 3.Bf4

    Develops the bishop to f4, bringing it into the game.

    Idea: Improve piece coordination and clear the back rank for castling and the rooks.

  6. 3c5

    Advances the c-pawn to gain queenside space and control new squares.

    Idea: Create useful wing space while keeping the central structure flexible.

  7. 4.e3

    Advances to e3 to claim central space and control nearby key squares.

    Idea: Give the pieces room to develop behind a durable central foothold.

  8. 4Qb6

    Repositions the queen to b6, where it influences a new part of the board.

    Idea: Coordinate threats carefully while avoiding unnecessary tempi against the queen.

  9. 5.Nc3

    Develops the knight to c3, bringing it into the game.

    Idea: Improve piece coordination and clear the back rank for castling and the rooks.

Book continuations

Waiting for Lichess game popularity.

0 moves
This is the end of the indexed line.

Named variations

Each line below is an indexed entry under London System. Open one to load it on the board and keep exploring from that position.

ECO groups openings by the structures they lead to, so these families tend to share plans with the London System.