Nimzo-Indian Defense: Spielmann Variation, Karlsbad Variation

When playing as White, the move d4 is often played in order to control the center of the board, especially the e5 square. It also allows for the development of the Queen's pawn and potential for the Queen to join the game. Playing d4 can put pressure on Black's position and limit their options, leading to a stronger White position. At the same time, it's important for White to be aware of Black's potential counterplay, including the Nimzo-Indian Defense.

As Black, playing Nf6 on move two allows for control of the e4 square and puts pressure on White's pawn structure. It also prepares for potential development of the Knight to g4, pinning White's knight on f3. Additionally, Nf6 allows for flexibility in Black's pawn structure, as the pawn on e6 can potentially move to d6 or d5 depending on the game's development. In sum, Nf6 is a solid and flexible opening move for Black.

Playing c4 as White supports the pawn on d4 and establishes a strong presence in the center of the board. It also prepares for the development of the Queen's Knight to c3. By controlling the d5 square, White limits Black's options and can potentially gain a positional advantage. Additionally, c4 allows for flexibility in White's pawn structure, as the pawn can potentially advance to c5, controlling even more space on the board. In sum, c4 is a strong and flexible opening move for White.

In the Nimzo-Indian Defense: Spielmann Variation, Karlsbad Variation, Black plays e6 in order to establish more control over the d5 square and prepare for the development of the light-squared Bishop to b4. Additionally, e6 can support the pawn on d5, potentially forcing White to advance their pawn to c5 and create a tension in the center of the board. Black could also use e6 to potentially fianchetto their dark-squared Bishop for added control over the center of the board. In sum, e6 is a flexible move that can lead to various pawn structures and positional advantages for Black.

Playing Nc3 as White after 1. d4 Nf6 2. c4 e6 supports the pawn on d4 and establishes further control over the center of the board. The Knight on c3 also prepares for potential development to attack Black's pawn on d5. Additionally, by placing a minor piece on the board, White begins to develop their pieces and establish control over more squares. In some cases, Nc3 can also prepare for potential Knight maneuvers, such as Ne2-f4 or Nc3-d5. In sum, Nc3 is a solid and flexible opening move for White that helps support their center control and piece development.

Playing Bb4 as Black after 1. d4 Nf6 2. c4 e6 3. Nc3 puts immediate pressure on White's Knight, potentially forcing it to move or be exchanged for Black's Bishop. Additionally, Bb4 develops a minor piece and supports Black's control over the d5 square, further limiting White's options and mobility in the center of the board. The pin created by Bb4 can also lead to tactical opportunities for Black, such as potential attacks on White's Queen or pawn structure. In sum, Bb4 is a strong and aggressive opening move for Black that can create immediate pressure and lead to potential positional and tactical advantages.

In the Nimzo-Indian Defense: Spielmann Variation, Karlsbad Variation, playing Qb3 as White after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 allows White to target Black's pawn on c5 and create potential pressure on Black's backwards pawn structure. Additionally, Qb3 directly attacks Black's Bishop on b4, forcing it to either move to a less active square or be exchanged for White's Queen, gaining White a tempo. Qb3 also prepares for potential development of White's light-squared Bishop to d2, where it can potentially support the pawn on e3 and prepare for future maneuvers. In sum, Qb3 is a strong and aggressive move for White that creates immediate pressure on Black's position.

By playing c5 as Black after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3, Black gains more control over the center of the board and stakes a claim on the d4 square. Additionally, c5 can support Black's Bishop on b4, potentially leading to attacks on White's pawn structure or piece development. Playing c5 can also create a tension in the center of the board and force White to make decisions regarding their pawn structure and potential pawn exchanges. In sum, c5 is a strong and flexible response for Black that supports their control over the center of the board and can lead to potential positional and tactical advantages.

By playing dxc5 as White after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5, White aims to open up lines for their Queen and Bishop while simultaneously creating pressure on Black's pawn structure and gaining space in the center of the board. Taking on c5 also allows White to potentially support their pawn on d4 with c5 and gain a powerful pawn duo. Additionally, dxc5 can create an isolated pawn on d5 for Black, potentially leading to future weaknesses in their pawn structure and positional advantages for White. In sum, dxc5 is a strong and aggressive move for White that can lead to potential tactical and positional advantages.

In the Nimzo-Indian Defense: Spielmann Variation, Karlsbad Variation, playing Nc6 as Black after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5, aims to put pressure on White's pawn on d4 and control over the center while simultaneously developing a minor piece. Additionally, Nc6 prepares for a potential attack on White's pawn on e5 or to support Black's pawn on d5 if necessary. By placing a Knight on c6, Black also saves their pawn on e6 from being overprotected by a Bishop, potentially freeing the Bishop for future maneuvers. In sum, Nc6 is a flexible and dynamic move that contributes to Black's overall development and puts pressure on White's position.

Playing Nf3 as White after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6 allows White to further develop their Knight and add support to their pawn on d4. Additionally, Nf3 prepares for potential pawn exchanges in the center of the board and gains control over the e5 square. By developing a minor piece, White continues to establish control over more squares on the board and can potentially prepare for future attacks or positional advantages. Nf3 also helps defend against potential attacks on White's pawn structure, leading to a more solid and flexible position overall. In sum, Nf3 is a strong and flexible move for White that contributes to their continued development and control over the board.

Playing Ne4 as Black after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6 6. Nf3, attacks White's Bishop on b4 and can potentially force a desirable exchange for Black. Additionally, Ne4 introduces a powerful Knight to the center of the board and increases Black's control over the squares around White's pawn on d4. Black could also use Ne4 to place pressure on White's pawn structure and open up lines for their Queen or rook. In sum, Ne4 is a dynamic and aggressive move for Black that can potentially create immediate tactical opportunities and long-term positional advantages.

In the Nimzo-Indian Defense: Spielmann Variation, Karlsbad Variation, playing Bd2 as White after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6 6. Nf3 Ne4 is primarily a defensive move, getting out of the pin of the Bishop on b4 and protecting the pawn on c3. Additionally, Bd2 opens up a potential retreat square for White's Queen if necessary. By developing a minor piece, White continues to establish control over more squares on the board and can potentially prepare for future attacks or positional advantages. In sum, Bd2 is a solid and flexible move for White that helps to free their position from the constraints of Black's Bishop on b4.

Playing Nxd2 as Black after 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qb3 c5 5. dxc5 Nc6 6. Nf3 Ne4 7. Bd2, aims to exchange a potentially dangerous Bishop for White's Knight, in some cases creating doubled pawns for White. By removing the Knight from the board, Black can potentially gain more control over the d4 square and loosen White's pawn structure. Additionally, Nxd2 frees up Black's Bishop on c8 and opens up potential lines for their Queen or other pieces. In sum, Nxd2 is a strategic and potentially advantageous move for Black if played at the right moment, leading to potential tactical and positional advantages.