French Defense: MacCutcheon Variation, Advance Variation

The move e4 in the French Defense aims to control the center and free White's pieces. By playing e4, White puts pressure on Black's pawn on d5 and makes it difficult for Black to develop their pieces. The move also opens up the diagonal for the bishop and a potential attack on Black's kingside. However, playing e4 too early can lead to weaknesses in White's position and Black can take advantage of this.

Black's move e6 in response to e4 aims to control the center and prepare to develop the knight on f6. By playing e6, Black also prevents White from playing d4, which would further increase White's control over the center. The move also prepares to support the pawn on d5, which can be attacked by White's pieces. However, playing e6 too early can give White a chance to seize the initiative and develop their pieces with more freedom.

White's move d4 in response to e6 aims to gain full control of the center and challenge Black's pawn on d5. With d4, White frees their light-squared bishop and knights for development while putting pressure on Black's pawn chain. If Black captures on d4, White takes back with the queen, gaining more control over the center and exerting pressure on Black's position. However, playing d4 too early could leave White's center pawns vulnerable to attack, and Black can take advantage of this by developing their pieces to attack the center.

In the French Defense: MacCutcheon Variation, Advance Variation, Black's move d5 aims to establish control over the center by challenging White's pawn on d4. By playing d5, Black also frees their light-squared bishop and prepares to develop their pieces. The move can also limit White's options for developing their pieces and puts pressure on White to make an early decision on how to capture the pawn. However, playing d5 too early can lead to an unbalanced position where Black's pawn structure may become weak, especially if White manages to attack the c3-knight and force Black to capture with the pawn.

White's move Nc3 in response to Black's d5 aims to put pressure on the pawn on d5 and gain control of the center. By developing the knight, White also clears the way for the dark-squared bishop and prepares to castle. Additionally, the knight on c3 puts pressure on Black's pawn on e6, potentially limiting the mobility of Black's pieces. However, playing Nc3 too early can also allow Black to trade their bishop for the knight, resulting in a favorable pawn structure for Black.

Black's move Nf6 in response to Nc3 aims to develop a piece and put pressure on the pawn on d4. The knight on f6 also prepares to castle kingside and supports the pawn on d5, which could come under attack by White's c3-knight or light-squared bishop. Additionally, the knight on f6 controls important central squares and can be used to launch a counterattack against White's center. However, playing Nf6 too early can also allow White to gain control of the center by playing e5, attacking the knight and forcing it to retreat.

In the French Defense: MacCutcheon Variation, Advance Variation, White's move Bg5 aims to pin Black's knight on f6 to their queen, potentially weakening Black's kingside. The move also develops the bishop and puts pressure on Black's pawn chain. If Black decides to capture on g5, White can recapture with the h-pawn, opening up the h-file for potential attack. However, playing Bg5 too early can also allow Black to play h6 and force the bishop to retreat, losing time and allowing Black to further develop their pieces.

Black's move Bb4 in response to Bg5 aims to attack the knight on c3 and force White to make a decision on how to defend it. If White plays a3, Black can develop their bishop to a6, potentially forcing White to weaken their pawn structure. The move also develops a piece and pins White's bishop to their queen. The pin can limit the bishop's mobility and pressure it to retreat. However, playing Bb4 too early can also allow White to play cxd5, trading pawns and delaying Black's development.

White's move e5 in response to Bb4 aims to drive away the bishop and potentially open up lines of attack against Black's position. The move also gains more space in the center and threatens to win a pawn by attacking the bishop on b4. If Black decides to capture on e5, White can respond with dxe5, gaining control over the center and opening up positions for their pieces. However, playing e5 too early can also leave White's position vulnerable to attack and allow Black to take control of the position by preparing a counterattacking strategy centered around their pieces.