Blackmar-Diemer Gambit: Zeller Defense

In the Blackmar-Diemer Gambit: Zeller Defense, white opens with 1. d4, which aims to occupy the center of the board and free the light-squared bishop. This move creates pawn tension in the center and restricts black's options to develop their pieces. White is now prepared to follow up with the aggressive move e4, which intends to offer the pawn and force black to make a consequential decision. The d4 pawn also supports other potential moves, such as bringing the knight to c3 to attack the e4 pawn if black chooses to accept the gambit. In sum, 1.d4 is a powerful move that allows white to shape the game's direction on their terms.

Black's move d5 is a solid response to white's d4. This move aims to control the central squares and limit white's options to expand in the center. By advancing the d-pawn, black frees up their light-squared bishop and prepares to bring out their knights. Moreover, d5 also helps to maintain pawn symmetry and counteract any potential threats to black's position. This move also hinders white's chances of playing the pawn to e4, which would have disrupted black's pawn structure and given white a strong central pawn. In summary, d5 is a sensible move that aims to create a solid foundation for black's pieces.

White's move e4 is an attempt to gain control over the center by advancing the pawn to its most aggressive square. By doing this, white aims to open up lines of attack for their bishop and queen. If black decides to capture the pawn, then white gains a lead in development and can put pressure on black's position. White can follow up with moves such as Nd2, Bf4 or Nf3 to build on the pawn's advance, support the pawn and develop other pieces effectively. Playing e4 can also discombobulate black's pawn structure, making it more difficult for them to get their pieces out. However, playing e4 also means that the pawn is undefended and may be vulnerable to attack. In sum, e4 is a strong and attacking move that aims to seize control of the game from the outset.

In the Blackmar-Diemer Gambit: Zeller Defense, black's move dxe4 aims to capture the pawn offered by white. If black succeeds in capturing the pawn, they gain material advantage at the cost of pawn structure. However, the position becomes more open, and white has a lead in development. Capturing the pawn also counters white's aggressive strategy by halting the pawn's advance and reducing the number of targets for their bishop and queen. Moreover, if white doesn't develop any pieces, the black queen can put pressure on white's king sooner than expected. However, black must also be aware of possible follow-ups by white, such as Nc3 and Bg5, which can cause discomfort to black's position. In sum, capturing the pawn can be tempting, but it requires careful attention to the ensuing developments.

White's move Nc3 in response to Black's dxe4 aims to support the pawn on e4 and bring out a knight to a central square. Nc3 also puts pressure on Black's queen pawn, d5, and threatens to attack it again if it moves. The knight also supports the possibility of playing f3 later, reinforcing the pawn on e4. Moreover, the knight can also help White to control other key squares, such as d5 and e5. By developing the knight and consolidating the center, White prepares for potential future attacks. However, Nc3 can also free Black's light-squared bishop to attack the pawn on e4, which may require White to make a careful defensive move. In sum, Nc3 is a reasonable move for developing and consolidating White's position in the center.

Black's move Bf5 aims to develop a piece, attack the pawn on e4 and simultaneously defend the pawn on d5. Bf5 also pins the knight on c3 to the queen on d1, making it difficult for White to move the knight without losing material. Moreover, Bf5 increases the pressure on the pawn on e4 since the bishop now eyes the pawn with two pieces - the pawn on d5 and the bishop itself. By playing Bf5, Black also prepares to castle and connects the rooks, helping to complete their development. However, Black must be careful not to lose time by moving the bishop too many times in the opening, as this can give White an opportunity to make a powerful move elsewhere on the board. In sum, Bf5 is a pragmatic move that aims to develop a piece, attack and defend pawns simultaneously, and prepare for castling.