Grünfeld Defense: Three Knights Variation, Petrosian System

The move 1. d4 by White is a very common move in the opening of the game of chess. White intends to control the center of the board with this move and create a solid foundation for a strong pawn structure. By advancing to d4, White indirectly attacks the black knight on f6, which is a key defender of the center. This forces Black to respond with a move, and one of the most popular responses is with 1...Nf6. From here, White continues with the development of their pieces and aims to maintain control over the center of the board.

Black's move 1...Nf6 is a logical response to White's opening move. By placing the knight on f6, Black seeks to challenge White's control over the center of the board. Nf6 also prepares for possible pawn advances by Black, such as a later move to d5. Additionally, the knight on f6 provides support for Black's c7 pawn and makes it more difficult for White to have a strong pawn center. In sum, 1...Nf6 is a flexible move that allows Black to react to White's future plans.

The move 2. c4 by White is a standard response to Black's move 1...Nf6. With this move, White aims to control the center of the board by attacking Black's d5 pawn. The move also prepares for the development of White's pieces, particularly the knight on c3 and the queen on d1. By advancing c4, White also gains space on the board and limits Black's options for pawn advances. In sum, c4 is a strong move that allows White to establish a solid foundation for a successful opening.

In the Grünfeld Defense: Three Knights Variation, Petrosian System, Black's move 2...g6 is a common response to White's move 2. c4. By moving the pawn to g6, Black prepares to fianchetto their bishop and create a solid defense on the kingside. This move also allows Black to gain control over the d5 square, which can be a key point of contention in the opening. Additionally, the move g6 is a flexible move that allows Black to react to White's future plans. In sum, g6 is a solid move that helps Black establish a strong position in the opening.

White's move 3. Nc3 in this position is a natural development move aimed at controlling the center of the board. The knight on c3 also provides support for White's pawn on d4, making it more difficult for Black to challenge White's control of the center. Additionally, Nc3 prepares for the possible capture of Black's d5 pawn, or a later move to e4. By developing the knight to c3, White also clears the way for the castle and allows the king to get to safety. In sum, Nc3 is a solid move that helps White to establish a strong position in the opening.

Black's move 3...d5 in this position is a central pawn break aimed at challenging White's control over the center of the board. By advancing the pawn to d5, Black aims to gain control over the important central squares and activate their pieces. Additionally, the move d5 creates a direct threat to White's pawn on c4, which must be defended. This can lead to exchanges in the center of the board and creates opportunities for both sides to develop their pieces. In sum, d5 is a confident move that allows Black to take control of the position and put pressure on White's opening strategy.

In the Grünfeld Defense: Three Knights Variation, Petrosian System, White's move 4. Nf3 is a standard development move aimed at contesting Black's control over the center of the board. The knight on f3 also supports White's pawn on d4 and prepares for the possible capture of Black's pawn on d5. Additionally, by developing the knight to f3, White clears the way for the castle and allows the king to get to safety. Nf3 is also useful in allowing White to bring their other pieces into play, particularly by supporting the bishop on g5. In sum, Nf3 is a flexible move that puts pressure on Black and enables White to establish a strong position in the opening.

Black's move 4...Bg7 in this position is a standard move that develops the bishop and prepares for the castling of the king. By fianchettoing the bishop on g7, Black can protect their own pawn on f6 and control important diagonal squares. The bishop on g7 also puts pressure on White's pawn on d4 and can be used to attack White's center. Additionally, Bg7 prepares for the possible exchange of the light-squared bishops, which can give Black an advantage in controlling dark squares. In sum, Bg7 is a flexible move that helps Black to establish a strong position in the opening.

White's move 5. Bg5 in this position is a natural development move that aims to put pressure on Black's position. By moving the bishop to g5, White pins Black's knight on f6, which cannot move without losing a piece or pawn. This also makes it difficult for Black to develop their pieces and control important central squares. Additionally, the move Bg5 puts pressure on the pawn on d5 and prepares for the possible exchange of the dark-squared bishops. In sum, Bg5 is a strong move that allows White to establish a solid position and puts pressure on Black's flexibility and development.