Queen's Indian Defense: Fianchetto Variation, Nimzowitsch Variation

The Queen's Indian Defense is a popular opening in chess, played by black in response to white's opening move d4. This opening allows black to control the center of the board and develop their pieces quickly. White's d4 move is the starting point for this opening, aiming to gain control of the center by occupying the d5 square. This move also prepares for the development of the queen's pawn and knight. With the Queen's Indian Defense, black aims to contest white's control of the center and prepare their pieces for an aggressive attack.

When responding to the d4 opening move, Black plays Nf6 to immediately challenge White's control of the center of the board. By occupying the central squares with a pawn and knight, White lays the groundwork for a strong and aggressive position. Playing Nf6 not only stakes a claim to the central squares but allows Black to develop their knight and pave the way for future attacks. Additionally, by challenging White's position, Black can prevent White from executing their preferred strategy and potentially force them into a defensive position.

White plays c4 to gain control of the center of the board and create a pawn chain alongside the d-pawn. By doing this, White not only reinforces their control over the central squares but also creates additional development opportunities for their pieces. Additionally, c4 prepares for the development of White's knight and bishop, which can occupy powerful central squares and move towards Black's side of the board. In sum, c4 is played to solidify White's control of the board and aggressively prepare for future moves.

In the Queen's Indian Defense: Fianchetto Variation, Nimzowitsch Variation, Black plays e6 as a preparatory move, aimed at developing their dark-squared bishop while allowing their queen's pawn to move to d5. By blocking the pawn on c4, Black restricts the mobility of White's knight and bishop, limiting their ability to occupy important central squares. Additionally, e6 prepares for the eventual development of Black's light-squared bishop, which can be deployed to support their center or put pressure on White's pawn chain. In sum, e6 is played with the aim of gaining control over the central squares and creating long-term opportunities for Black's pieces.

Having played c4 and e6, White's position has become more cramped and Nf3 is played to help release the pressure by developing a knight and preparing for the eventual kingside castle. By placing the knight on f3, White also gains control over the important central squares and prepares for future attacks on Black's position. The knight can also move towards the center and support any future attacks initiated by White's pawns and pieces. In sum, Nf3 is a flexible move that furthers White's development and ensures a strong position on the board.

In response to Nf3, Black plays b6 as a preparatory move to fianchetto their dark-squared bishop to b7. Placing the bishop on this diagonal not only increases its scope but also helps control key central squares and limits White's potential pawn advances. Additionally, b6 prepares for a future queenside castle, while paving the way for the development of Black's c8 bishop. By challenging White's position and holding on to their own strategic plans, Black can maintain control of the game and limit White's options. In sum, b6 allows Black to develop their pieces effectively while advancing their own agenda on the board.

In the Queen's Indian Defense: Fianchetto Variation, Nimzowitsch Variation, White plays g3 to establish a strong pawn structure and prepare for the fianchetto of their own light-squared bishop to g2. By castling kingside and placing the bishop on this long diagonal, White can control key squares and initiate attacks on Black's position. Additionally, g3 reinforces White's position and bolsters their defense against potential counterattacks. The pawn move can also pave the way for the eventual development of White's knight to g2, which can support these attacks and control additional squares. In sum, g3 is a flexible move that allows White to maintain a strong position while developing their own pieces.

When playing against g3, Black responds with Ba6, targeting White's knight on f3 for exchange. This move can also put significant pressure on White's pawn structure and restrict the mobility of the light-squared bishop. By controlling the a6-f1 diagonal, Black strengthens their own position and creates opportunities for counterattacks against White's pieces. Additionally, Ba6 prepares for the eventual queenside castle and allows Black to develop their light-squared bishop to b7. In sum, Ba6 is a flexible move that gives Black multiple options while maintaining strategic pressure on White's position.