Ruy Lopez: Morphy Defense, Mackenzie Variation

In the Ruy Lopez: Morphy Defense, Mackenzie Variation, White begins by playing e4. This move aims to control the center of the board, allowing White to develop their pieces more effectively. By occupying the center, White puts pressure on Black to respond and make good use of their own central pawns. This move also prepares for the bishop to be developed, which will enable White to castle kingside and put their king in a safer position.

Black responds to e4 with e5, aiming to challenge White's control over the center of the board. By placing their pawn on e5, Black gains a foothold in the center and prepares to develop their own pieces. This move also sets up a potential attack on White's pawn, putting pressure on White to defend it. Additionally, e5 allows Black's own bishop to be developed, enabling them to castle kingside and put their own king in a safer position.

White follows up with Nf3 to further control the center and bring a knight into play. This move prepares to support the pawn on e4 if attacked by black's knight on c6. Additionally, the knight on f3 makes way for White's bishop to be developed on its ideal square. Finally, Nf3 sets up the possibility of a kingside attack with the knight eventually being supported by pawn advances.

In the Ruy Lopez: Morphy Defense, Mackenzie Variation, Black responds to Nf3 with Nc6. This move develops a knight and puts pressure on White's central pawn on e4. The knight also eyes the d4 square, which could become a strong outpost for a knight in the future. Furthermore, Nc6 supports Black's pawn on e5 and prepares for the bishop to be developed. This move may also lead to the opportunity to play the fork tactic ...Nxd4, attacking White's bishop on b5 and their pawn on e4 simultaneously.

White plays Bb5 in order to pin Black's knight on c6 to their queen. This move introduces a new attacking piece and also prevents Black from playing ...d6, which is an important move in many variations of the Ruy Lopez. By placing their bishop on b5, White also prepares to castle kingside and brings their bishop to a potentially active square, eyeing several key points on the board. Finally, Bb5 puts pressure on Black's pawn on e5, possibly allowing White to capture it by means of a discovered attack later in the game.

Although White's bishop on b5 is often an important piece in many variations of the Ruy Lopez, in this particular position, Black responds with a6 to disrupt White's plans. This move forces the bishop to retreat or be captured, and also prepares ...b5 to challenge White's control over the c4 square. Additionally, by playing a6, Black secures a square on b5 for their own pieces in the future, and minimizes the potential for a pin on their knight by a future bishop move from White. Finally, a6 can prevent potential checkmates on the a7-g1 diagonal in some lines.

In the Ruy Lopez: Morphy Defense, Mackenzie Variation, White responds to Black's a6 with Ba4. This move may seem like a retreat, but it serves several important purposes. Firstly, Ba4 puts pressure on the black pawn structure, indirectly attacking the pawn on e5. Secondly, White brings a bishop out in the open where it can influence more squares on the board. Thirdly, Ba4 allows White to castle kingside without blocking in the bishop on c1. Finally, Ba4 is useful in the sense that it threatens to exchange bishops with Black if they retreat their bishop to b7, in which case White can exchange their less valuable bishop for Black's stronger one.

Black plays Nf6 in order to develop a piece, and also to control the central squares d5 and e4. By advancing the knight, Black prepares to castle kingside and brings another attacking piece into play. Additionally, Nf6 often leads to the possibility of playing ...d6 and ...Bg4, putting pressure on White's pawn structure and forcing further development of their pieces. Finally, Nf6 is also a flexible move that can lead to several different variations, making it difficult for White to predict Black's strategic intentions.

White's move d4 in the Ruy Lopez: Morphy Defense, Mackenzie Variation, aims to control the center and open up lines for their pieces. This move puts pressure on Black's pawn on e5 and prepares the way for White's central pawns to be advanced. By opening up space in the center, White's pieces gain more mobility, particularly the queen and the light-squared bishop once the pawn on d4 is established. Additionally, d4 blocks Black's bishop on c8, potentially rendering it ineffective for the rest of the game. Finally, d4 also prepares for a pawn push to e5 which would fork Black's knight on f6 and bishop on c8 later in the game.