Nimzo-Indian Defense: St. Petersburg Variation, with Ne4

This opening is a solid choice for Black, aiming to control the center and develop pieces harmoniously.

The St. Petersburg Variation with Ne4 is a popular line in the Nimzo-Indian Defense, where Black immediately targets the c3 knight to disrupt White's pawn structure. By playing b6 and Bb7, Black prepares to fianchetto the dark-squared bishop and put pressure on the center. The move Ne4 is a key idea in this variation, aiming to exchange the knight on c3 and potentially create weaknesses in White's pawn structure. White has several options to respond, such as defending the knight on c3 or allowing the exchange. Black can then continue to develop pieces and castle kingside, while White must be careful not to fall into tactical traps or allow Black to gain a strong initiative. Overall, this variation leads to dynamic and complex positions where both sides have chances for an interesting game.