4.Nbd2 b6: the fianchetto answer is variation 6 of 6 in the Bogo-Indian Defence course, a intermediate opening course for Black (ECO E11). It runs 20 moves and begins 1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 4. Nbd2 b6 …. Black answers 4.Nbd2 with a queenside fianchetto. After 5.a3 Black trades on d2 and puts the bishop on b7. Black castles, plays ...d6 and puts a knight on e4. In the lesson every move is explained on a board and then drilled; it is free.
Move by move
1. d4 – White takes the centre.
1... Nf6 – Black develops and watches e4.
2. c4 – White gains space.
2... e6 – Black opens the f8 bishop.
3. Nf3 – White develops and avoids the pin on c3.
3... Bb4+ – The Bogo-Indian. Black develops with check.
4. Nbd2 – White blocks with the knight.
4... b6 – Black plans to fianchetto and fight for e4.
5. a3 – White asks the bishop at once.
5... Bxd2+ – Black trades the bishop for the knight.
6. Bxd2 – White takes back with the bishop and keeps the bishop pair.
6... Bb7 – The bishop controls e4.
7. e3 – White opens the f1 bishop.
7... O-O – Black castles.
8. Bd3 – White develops the bishop toward the kingside.
8... d6 – Black keeps the d-pawn back and plans a knight on e4.
The lesson goes on for 4 more moves, each with its explanation.
chessGM