Bogoljubov–Mikenas Defense
The Bogoljubov–Mikenas Defense is a chess opening defined by the moves:
Unless the game transposes to another opening, the Encyclopedia of Chess Openings classifies the opening with the code A40.
Discussion
This opening was tried by some hypermodern players such as Aron Nimzowitsch and Efim Bogoljubov, but it has never become very popular. The move 1...Nc6 is a fairly committal move which blocks Black's c-pawn; usually Black delays playing it until White's setup is clear.Most games featuring 1.d4 Nc6 transpose to other openings. After 2.e4 the Nimzowitsch Defense arises. After 2.Nf3 d5 a variation of the Queen's Pawn Game is possible. After 2.c4 d5 the opening is a Chigorin Defense.
There are some lines that are unique to 1.d4 Nc6, most importantly 2.d5 which chases the knight away, usually to e5. The opening resembles an Alekhine's Defence but on the opposite side of the board. In an opening book by Sid Pickard, this variation was called the Bozo-Indian Defense, although it is not an Indian opening, as those involve the move...Nf6.
The Bogoljubov–Mikenas Defense was featured in the season four episode of Chuck entitled "Chuck Versus the Family Volkoff".
Transpositions
After 1.d4 Nc6 Black should be ready for various continuations; however, White cannot just ignore the fact that Black is ready to play...e5 in the next move. Therefore, practically speaking, White is likely to play the move 2.Nf3, trying to reach a position with a theoretical advantage. Black could respond to Nf3 with two main moves:- 2...d6 can transpose to the Pirc Defense or the King's Indian Defence if White plays an early c4. Unusual sequences after 2.Nf3 d6:
- *Dutch Defence – 3.g3 g6 4.Bg2 Bg7 5.0-0 f5 6.d5
- *Ruy Lopez – 3.e4 e5 4.Bb5 exd4 5.Qxd4
- 2...e6 can transpose to the Nimzo-Indian Defence, Bogo-Indian Defence and the Chigorin Defense if White plays c4 immediately. If White tries going for an open game, the game can transpose to a Guimard French or another French line with 4...e5, or the Nimzowitsch Defence.