Nimzo-Indian Defense: Normal Variation, Bronstein (Byrne) Variation

When starting with the first move d4, White aims to establish control over the central squares, d5 and e5, and limit Black's options for controlling them. This move also clears the path for the c1 bishop and the queen to become active. Additionally, d4 sets the stage for e2-e4, which can lead to a strong pawn center and potential attacks on Black's position.

When responding to d4 with Nf6, Black aims to control the central square e4 and put pressure on the d4 pawn. This move also develops the knight and prepares for future pawn advances to challenge White's central control. Moreover, Nf6 is a flexible move that does not commit Black to any specific pawn structure or opening line, enabling Black to adapt to White's move choices.

With the move c4, White looks to establish central control and support the d4 pawn. This move also opens up the path for the queen's bishop while developing the knight on c3. In addition, c4 prepares for the pawn advance d4-d5, which can potentially break apart Black's central pawn structure and create new weaknesses. Playing c4 in this position is a very common way for White to strengthen their position and control the center.

In the Nimzo-Indian Defense: Normal Variation, Bronstein (Byrne) Variation, when facing c4, Black often responds with e6 to support the d5 pawn advance and control the central squares. This move also allows the light-squared bishop to be developed and frees up the queen to move to a useful square if necessary. Moreover, e6 prepares for a potential future push of the f-pawn to f5, which can help Black gain more space and limit White's piece activity. In sum, e6 is a solid and flexible move, which allows for several different pawn structures and opening lines.

With the move Nc3, White develops a piece and adds pressure on Black's central pawn. This move also supports the d4 pawn and prepares for the potential pawn advance to e4. Moreover, Nc3 allows White to control the d5 square, which can be crucial for attacking Black's center. As one of the most common moves in this position, Nc3 is a solid choice that increases White's piece activity and sets the stage for future plans.

By playing Bb4, Black follows the principle of developing a minor piece and challenging White's control of the center. The bishop targets the c3 knight and can force it to move, allowing Black to gain better control over the d4 square. This move also prepares for a potential future pin of the knight along the b-file, which can be very uncomfortable for White. In sum, Bb4 is a flexible and aggressive move that can put early pressure on White and create some complications in the opening.

In the Nimzo-Indian Defense: Normal Variation, Bronstein (Byrne) Variation, one of the most common moves for White after Bb4 is e3. This move guards the d4 pawn and prepares for the bishop to be exchanged for the knight on c3 without creating any weaknesses in White's pawn structure. Moreover, e3 allows the light-squared bishop to be developed, either to d3 or e2, supporting the control over the central squares. Additionally, e3 prevents Black's knight on f6 from advancing to e4 and potentially attacking the d4 pawn. In sum, e3 is a solid and flexible move that supports White's position while maintaining a strong control over the center.

In response to White's e3 move, playing b6 is a common choice for Black as it develops the light-squared bishop and prepares to fianchetto it to b7. It also creates a potential battery against White's central pawns if the bishop is exchanged for the knight on c3. Additionally, b6 prepares for a potential pawn advance to c5, which can challenge White's center or create pressure on the d4 pawn. This move also enables the queen's bishop to become active along the long diagonal. In sum, b6 is a flexible and solid move for Black that offers a variety of plans and options for further development.

With the move Ne2, White develops the knight and prepares to castle kingside. This move also frees up the f1-square for the f1 bishop and allows the d4 pawn to be supported by another piece. Additionally, Ne2 keeps an eye on the c4 pawn and can prepare for a potential pawn push to f4, which can help to create a strong pawn center and restrict Black's pawn breaks. Moreover, this move can also allow a future exchange of the light-squared bishops, which can help to weaken Black's pawn structure. In sum, Ne2 is a flexible and versatile move that supports White's development and prepares for future plans.

In the Nimzo-Indian Defense: Normal Variation, Bronstein (Byrne) Variation, when facing Ne2, the move Ba6 is often played by Black. This move aims to pressure the knight on e2 and force it to move, disrupting White's piece coordination. It also eyes the c4 pawn and threatens to exchange the bishop for the knight on c3, potentially weakening White's pawn structure. Additionally, Ba6 prepares for a potential future bishop exchange along the a6-f1 diagonal, which can help Black gain control over the center and increase their piece activity. In sum, Ba6 is a flexible and aggressive move that creates some complications in the position and puts some pressure on White.