Nimzo-Indian Defense: Classical Variation, Berlin Variation, Steiner Variation

Chess begins with 1.e4 or 1.d4, and in this case, White chooses the latter. By playing d4, White looks to control the center of the board, gain space and develop the pieces, particularly the dark-squared bishop. This strong central pawn move also puts pressure on Black's position and limits their options, as they cannot immediately push their own d-pawn. The game then proceeds with 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 c5 5. dxc5 Bxc3+ to initiate the Nimzo-Indian Defense.

Black plays Nf6 after d4 to contest White's hold on the center of the board. By putting pressure on the d4-pawn, Black seeks to limit White's options and gain more space for their own pieces. Nf6 also prepares to develop the g8-knight, the dark-squared bishop, and possibly the f8-bishop, depending on the variation. In sum, Nf6 is a strong move aimed at equalizing the position and initiating counterplay.

White plays c4 with the intention of gaining control over the center of the board. By pushing this pawn, White aims to create a strong pawn duo with d4, which significantly restricts Black's pieces. The pawn also gives White the option of further expanding in the center with moves like e3, e4 or f3 if the position demands it. Additionally, c4 helps White develop the queen's knight to c3, which contests Black's control of the d5-square. In sum, c4 is a powerful move that sets the stage for aggressive play and control early on in the game.

In the Nimzo-Indian Defense: Classical Variation, Berlin Variation, Steiner Variation, Black plays e6 to support their own central pawn on d5 and to prepare the development of the light-squared bishop. The move also stops White from playing e4, which would be a strong central pawn advance that Black would find difficult to contest. By playing e6, Black limits the mobility of White's pieces and prepares to establish a solid pawn structure. Additionally, the move prepares for possible attacks on the kingside by opening up lines for the dark-squared bishop.

After 1.d4 Nf6 2.c4 e6, White's natural move is Nc3. This move develops a new piece and supports the d4-pawn in the center. The knight on c3 also controls the d5-square, which is one of the key central squares in the position. With Nc3, White prepares to castle kingside and completes their development. Additionally, Nc3 sets up pawn breaks like e4 or d5 in the future, which would further strengthen White's position and increase their control in the center. In sum, Nc3 is a solid move that helps White establish a flexible and versatile position early on in the game.

After 1. d4 Nf6 2. c4 e6 3. Nc3, Black plays Bb4, initiating the Nimzo-Indian Defense. This move pins the knight on c3 and puts pressure on White's center by attacking the d4-pawn indirectly. Furthermore, the move also prepares to exchange a key defender of the d4-pawn (the knight on c3) for Black's bishop, which would ease Black's control over the center. Bb4 also develops the bishop and prepares to castle queenside or kingside, depending on the variation. In sum, Bb4 is a strong move that creates immediate pressure and forces White to make decisions that will impact the rest of the game.

In the Nimzo-Indian Defense: Classical Variation, Berlin Variation, Steiner Variation, White plays Qc2 after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4. This move protects the d4-pawn and, at the same time, prepares to castle kingside. Qc2 also sets up a battery with the queen and bishop on the long diagonal, which can be a powerful attacking formation later in the game. The move also opens up the possibility of pushing the e-pawn forward to e4, which would further strengthen White's control over the center. Qc2 also allows White to avoid the exchange of the light-squared bishop, which is often a key defender in Black's position. In sum, Qc2 is an important move that consolidates White's position and sets the stage for strong play in the upcoming variations.

After 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2, Black plays c5 to challenge White's control over the center. This move also attacks the d4-pawn and puts pressure on White's queen, which is now forced to move away or exchange itself for a knight on c3. c5 also opens up lines for Black's pieces, including the queen's bishop and the queen, that can be used to launch attacks on the kingside or the center. Furthermore, c5 can be an important pawn break that leads to counterplay and even the possibility of winning material. In sum, c5 is a strong move that creates immediate pressure and offers Black a more dynamic and aggressive position in the game.

After 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 c5, White plays dxc5 with the intention of opening up the c-file for the queen. By capturing the b4-bishop with the pawn, White also gains control over the c5-square, which can be used to establish a strong outpost for the knight or a passed pawn later in the game. dxc5 also makes way for the queen's knight to go to d5, which attacks Black's weakened pawn structure and blocks one of Black's pieces. Furthermore, dxc5 can lead to the eventual capture of the c5-pawn with White's queen, which would force Black's queen to move away and leave other pieces vulnerable. In sum, dxc5 is a strong move that creates a more dynamic and aggressive position for White and puts pressure on Black to find strong counterplays.

In the Nimzo-Indian Defense: Classical Variation, Berlin Variation, Steiner Variation, Black plays Bxc3+ after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 c5 5. dxc5. This move serves two purposes; first, it opens up the long diagonal for the queen's bishop, which can be a powerful attacking piece in Black's position. Secondly, by exchanging the bishop for White's knight on c3, Black weakens White's control over the d5-square, which makes it easier for Black's pieces to exert influence over the center. Additionally, Bxc3+ can potentially drag White's king into the center of the board, thereby making it more difficult for White to castle kingside. In sum, Bxc3+ is a powerful move that creates immediate pressure and gives Black good prospects for counterplay.