Indian Defense: Colle System, King's Indian Variation

The opening move 1. d4 is a common choice for white in chess, establishing control over the central squares on the board. This move aims to challenge black's control over the same squares, while also preparing to bring white's pieces into the game. By playing Nf3 on the second move, white prepares to develop the kingside knight while also supporting the d4 pawn. The move e3 follows, supporting the pawn even further and allowing the light squared bishop to develop to d3. Finally, Bd3 is played, completing white's development and preparing to castle kingside. By following this opening sequence, white aims to establish a strong position and put pressure on black's defenses.

In response to white's opening move 1. d4, black typically plays Nf6. This move aims to control the central squares of the board and prepare to challenge white's control over them. By developing the knight, black also frees up the c8 bishop to be developed later. Additionally, the knight on f6 puts pressure on white's pawn on d4, discouraging white from pushing it forward immediately. In sum, playing Nf6 is a solid and flexible response to white's opening move and allows for a variety of different defenses to be played.

After the opening moves 1. d4 Nf6, white typically plays Nf3. This move aims to support the d4 pawn, defend against potential attacks on the e4 square and prepare to castle kingside. Additionally, the knight on f3 discourages black from playing moves like e5, which would challenge white's control over the center of the board. In sum, this move is a natural development move that solidifies white's control over key central squares and prepares for future moves.

In the Indian Defense: Colle System, King's Indian Variation, after the opening moves 1. d4 Nf6 2. Nf3, black usually responds with the move g6. This move prepares to fianchetto the kingside bishop and develop the bishop to g7. The move also puts pressure on white's control over the center of the board, by potentially allowing black to play d5 and challenge white's foothold on the d4 square. Additionally, g6 prepares to defend against any future attacks by white aimed at the kingside. In sum, the move g6 is a flexible and solid choice for black that prepares for future development and puts pressure on white's central control.

In response to the opening moves 1. d4 Nf6 2. Nf3 g6, white typically plays the move e3. This move prepares to support the d4 pawn and frees up the light-square bishop to be developed to d3, where it indirectly supports the central pawn duo. Additionally, the move e3 prepares to castle kingside and provides a strong foundation for white's position. The pawn on e3 also makes it more difficult for black to play moves like d5 and challenge white's central control. In sum, this move is a solid and flexible choice for white that prepares for future development and solidifies white's control over key squares.

In response to white's move 3. e3, black typically plays Bg7. This move aims to develop the last minor piece to the kingside and complete a fianchetto, placing the bishop on its most active diagonal. The bishop on g7 also puts pressure on the central squares of the board, potentially challenging white's control over them. Additionally, the bishop on g7 supports the e5 pawn break in certain variations and prepares to castle kingside. In sum, playing Bg7 is a flexible and natural move that coordinates well with black's previous moves and prepares for future development.

In the Indian Defense: Colle System, King's Indian Variation, after the moves 1. d4 Nf6 2. Nf3 g6 3. e3 Bg7, white's typical response is the move Bd3. This move aims to complete the development of white's bishops, and indirectly support the central pawn structure. The bishop on d3 is also able to put pressure on black's position, by potentially targeting the f5 pawn or creating threats down the diagonal. Additionally, the move prepares to castle kingside and provides a solid foundation for white's position. In sum, playing Bd3 is a logical and well-timed move that prepares for future development and puts pressure on black's position.

In response to white's move 4. Bd3, black usually plays the move d6. This move prepares to support the pawn chain of c7 and e7, while also potentially allowing for the development of the dark squared bishop to d7, which defends the e6 square. The move d6 also guards against any tactics involving a pawn push to e4, which could potentially open up the f-file for white's rook and create threats. Additionally, the move d6 prepares to control the central squares of the board and potentially support a pawn push to either e5 or d5, depending on the position. In sum, playing d6 is a solid and flexible move that prepares for future development and defends against potential threats.