|The Bogo-Indian is a chess opening characterised by the moves 1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+.|
The position arising after 1.d4 Nf6 2.c4 e6 is common. The usual move for white here is 3.Nc3, threatening to set up a big pawn centre with 4.e4. 3.Nf3 is sometimes played instead as a way of avoiding the Nimzo-Indian (which would follow after 3.Nc3 Bb4). After 3.Nf3, Black usually goes with 3...b6 (the Queen´s Indian) or 3...d5 (the Queen´s Gambit), but can instead play 3...Bb4+, the Bogo-Indian, named after Efim Bogoljubov. This opening is not so popular as the Queen´s Indian, but is occasionally seen at all levels.
White has three viable choices to meet the check: 4.Bd2 is the most common, 4.Nc3 is a transposition to the Nimzo-Indian while 4.Nbd2 is an alternative aiming to acquire the bishop for the knight or forcing black´s bishop to retreat. The move 4.Nfd2 is considered weak, as it needlessly brings a well-placed knight to a passive position.