Chess Opening Theory/1. d4/1...Nf6/2. Bf4/2...e6/3. e3/3...d5/4. Nd2/4...c5/5. c3/5...Nc6

= London System Main Line with Black ...e6 and ...c5 =

When Black faces the London System and adopts the sequence of moves '''1. d4 Nf6 2. Bf4 e6 3. e3 d5 4. Nd2 c5 5. c3 Nc6''', they employ a blend of classical central control and active piece development. Black's strategy in this line of the London System is centered around challenging the center, active piece deployment, and flexible pawn structures. Black aims to counteract White's plans and seize the initiative whenever opportunities arise. The strategy encompasses:


 * 1) Challenging the Center: With ...d5 and ...c5, Black directly challenges White's central pawns, aiming to break the typical pawn structures White might establish. The goal is to create a more dynamic game and avoid getting squeezed by a potential White pawn roller in the center.
 * 2) Active Knight Development: With ...Nf6 and ...Nc6, Black gets both knights to their most natural squares, pressuring the d4 pawn and supporting potential central pawn breaks.
 * 3) Flexible Bishop Deployment: In this setup, Black has options regarding the light-squared bishop. Depending on White's responses, the bishop can be fianchettoed with ...b6 and ...Bb7, or it can come out more traditionally with ...Bd6 or ...Be7.
 * 4) Queenside Counterplay: Black's ...c5 pawn break, combined with the knight on c6, allows for potential queenside operations. Moves like ...Qb6, targeting the b2 pawn, or doubling rooks on the c-file, can generate tangible threats.
 * 5) Central Pawn Breaks: Depending on White's setup and pawn structure, Black can look for a timely ...e5 or ...d4 pawn thrust, opening up the center and freeing their pieces.
 * 6) King Safety: Depending on the flow of the game, Black can opt for a short castle with ...Be7 followed by ...O-O. If the game becomes more open and there are potential tactics or threats on the kingside, Black might consider a long castle, though it's less common in these structures.
 * 7) Trade Considerations: Given White's active dark-squared bishop on f4, Black might seek to exchange it with ...Bd6 at the right moment. Removing this bishop can neutralize some of White's pressure and make Black's game easier to play.

Theory table
. '''1. d4 d5 2. Bf4 Nf6 3. e3 e6 4. Nd2 c5 5. c3 Nc6'''