Nimzo-Indian Defense: Sämisch Variation, Accelerated

One of the reasons why White initiates with the move d4 is to control the center and occupy it with a pawn. The pawn on d4 exerts pressure on the black knight which can be chased away with the following move c4. Additionally, the move d4 opens up lines of development for the white bishop and queen. These advantages give White early control of the board and a strong platform to launch an attack.

By moving his knight to f6, Black controls the e4 square and prepares his own threats against White's center. The move is also a well-known response to White's queen pawn opening and is used in many different defenses. Additionally, the knight on f6 can be followed up with moves like d5 and e6 to solidify Black's central control and mount his own attack.

The move c4 by White is known as the Queen's Gambit and is a classic opening aimed at controlling the central squares of the board. By advancing the pawn to c4, White supports his pawn on d4, putting pressure on Black's knight on f6 and preparing for a future attack on Black's center. Additionally, the move opens up a potential avenue for the development of the c1 bishop and the queen, while also creating a weakness on the d5 square, which Black may try to exploit.

In the Nimzo-Indian Defense: Sämisch Variation, Accelerated, Black's move e6 is aimed at reinforcing his control of the central squares. The move is commonly seen in different openings and serves the purpose of supporting the pawn on d5 and helping to develop the bishop, which can be fianchettoed to the g7 square. Moreover, the pawn on e6 acts as a barrier which prevents White's knight on c3 from attacking Black's pawn on d5, a crucial point in several variations of the Nimzo-Indian Defense.

By moving his knight to c3, White develops a piece and helps to control the central squares. The move also prepares the pawn advance to d4, which aims to further control the center and challenge Black's pawn on d5. Additionally, the knight on c3 can also be used to support a future pawn push to e4, potentially creating a strong pawn center. The move also puts pressure on Black's bishop on b4, which may need to be moved, allowing White to gain additional tempo and control over the board.

In this position, Black's move Bb4 pinches White's knight on c3 and puts pressure on his center. The move also develops a piece and forces White to make a decision about how to defend his knight. If White decides to defend the knight with a3, Black can then capture the bishop on c3 with his bishop, doubling White's pawns and potentially creating a weakness. Alternatively, if White chooses to leave the knight undefended, Black may be able to capture it with his knight, again disrupting White's pawn structure.

In the Nimzo-Indian Defense: Sämisch Variation, Accelerated, White's move a3 is played to drive away Black's bishop on b4 and gain control over the c3 square. The pawn move also prevents Black from pinching White's knight on c3 and attacking it with his queen or other pieces. Additionally, a3 prepares the long castle for White, allowing him to put his king in a safe position on the kingside. The move comes at the cost of weakening the b3 square, which Black can potentially exploit in the future.

Black's move Bxc3+ is designed to ruin White's pawn structure and grab control over the center. By capturing White's pawn with his bishop, Black forces White to recapture with his b-pawn, creating a doubled pawn on the c-file that could be an easy target for Black's pieces. Furthermore, by capturing with the bishop, Black can potentially develop his queen to b6, putting pressure on White's pawn on d4 and restricting the movement of his pieces. The move Bxc3+ also eliminates White's bishop on this diagonal, making it difficult for White to control this important diagonal.

In this position, White's move bxc3 is aimed at consolidating his control over the center by recapturing Black's bishop with his pawn and establishing a pawn chain on c3 and d4. While the move leads to the creation of doubled pawns on White's c-file, White has the potential to develop his queen's knight to c3 and his queen's bishop to d3, allowing for the development of both these pieces and the potential to launch a future attack against Black's kingside. The move also eliminates any potential threats from a future Black move Qb6, as there is no longer a pawn on b2 to attack.