Queen's Gambit Accepted: Alekhine Defense, Haberditz Variation

Chess is a game that's full of intricate moves and strategies. One popular opening is the Queen's Gambit, which involves White offering a pawn to the opponent to control the center of the board. The move d4 is the start of the Queen's Gambit, as it provides an anchor in the center of the board while also opening both the bishop and the queen for action later in the game. The aim is to occupy the central squares with pawns and pieces, which leads to control over the board and a greater chance of success.

When Black plays d5 in response to White's d4 move, they also claim their share of the center of the board. This move creates a pawn chain that controls important squares, and it also opens up avenues for Black's pieces to move out. This pawn can also protect the bishop on the square c8, which can be developed afterwards. Additionally, pushing the pawn up to d5 makes Black's pawn structure more symmetrical to White's pawn structure, which is generally considered a good defensive approach.

When White plays c4 in response to Black's d5 move, they aim to control more central squares on the board. This move creates a pawn duo that dominates the center, preparing the way for the queen and bishop to be developed. By playing c4, White can also attack Black's pawn on d5, which would force Black to move their queen or knight and temporarily weaken their position. This move also prepares for the possibility of offering the Queen's Gambit, which can lead to a number of different lines and outcomes. In sum, c4 is a strong and flexible move that sets White up for a successful midgame.

In the Queen's Gambit Accepted: Alekhine Defense, Haberditz Variation, when Black plays dxc4 in response to White's c4 move, they accept the gambit by capturing White's pawn. This move allows Black to gain a foothold in the center of the board by controlling the important d4-square. Moreover, Black can now develop their light-squared bishop to c5 or f6, putting pressure on White's central pawns. This move also opens up the possibility of attacking the central pawn on e4 with moves such as Nd5 or Nf6. Therefore, dxc4 is a solid and active response by Black to White's Queen's Gambit.

When White plays Nf3 in response to Black's dxc4 capture, they are attacking the pawn on c4 with their knight. By moving the knight to f3, White also develops a piece and controls an important central square. This move also prepares for further development of the light-squared bishop, which can be fianchettoed to g5 or e3. Additionally, the knight on f3 can be used to defend the central pawn on e4 and support future attacks against Black's position. In summary, Nf3 is a solid and flexible move that allows White to continue developing their pieces while maintaining control over the center of the board.

When Black plays a6 in response to White's Nf3 move, they are preventing White from advancing their pawn to b5 and attacking Black's knight on c6. This move allows Black to protect their pawn on b5 and maintain control over the central square c5. Moreover, Black can use a6 to prepare for the further development of their bishop on b7, which can be directed towards the vulnerable light-squared pawns in White's position. Additionally, a6 prevents White from harassing Black's knights with moves like Ba4, and as such, it is considered a useful prophylactic move in many Queen's Gambit Accepted lines. Therefore, a6 is a solid and flexible move that helps strengthen Black's position and sets them up for a successful midgame.

In the Queen's Gambit Accepted: Alekhine Defense, Haberditz Variation, when White plays e3 in response to Black's a6 move, they are preparing to develop their light-squared bishop to a2 or e2 and potentially support a later pawn push to d4. This move also prevents Black's knight from attacking the pawn on c2 and stabilizes White's pawn structure. Moreover, the pawn on e3 acts as a strong defender for the pawn on d4, which can be critical in many Queen's Gambit Accepted lines. Additionally, e3 lays the groundwork for potential pawn breaks with f4 or d5, depending on how the game progresses. Therefore, e3 is a solid and flexible move that sets White up for a successful midgame while also defending their position.

When Black plays b5 in response to White's e3 move, they aim to control the square c4 and gain more space on the queenside of the board. This move also targets White's pawn chain and pressure the pawn on c4 to potentially induce weakness in White's position. Moreover, b5 helps Black develop their pieces more effectively, particularly the light-squared bishop on c8 which can be fianchettoed to b7. Black can also undermine White's pawn structure with moves like c6 or d4, forcing White to make difficult decisions about how to maintain their position. Therefore, b5 is a flexible and active move that puts pressure on White to make informed decisions while giving Black opportunities for counterplay.