4.Bd2 Bxd2+: the exchange line is variation 4 of 6 in the Bogo-Indian Defence course, a intermediate opening course for Black (ECO E11). It runs 26 moves and begins 1. d4 Nf6 2. c4 e6 3. Nf3 Bb4+ 4. Bd2 Bxd2+ …. The simplest choice. Black trades bishops, castles and puts a pawn on d5. Later Black frees the game with ...dxc4 and ...c5 and reaches an equal position. 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. Bd2 – White blocks the check.
4... Bxd2+ – Black trades bishops and develops quickly.
5. Qxd2 – White takes back with the queen and keeps the b1 knight free for c3.
5... O-O – Black castles.
6. Nc3 – White develops toward the centre.
6... d5 – Black takes a firm place in the centre.
7. e3 – White supports d4 and opens the f1 bishop.
7... Nbd7 – The knight develops and supports a later push to c5 or e5.
8. Rc1 – The rook goes to the c-file, where the game may open.
8... c6 – Black makes d5 even stronger and gets ready to take on c4.
The lesson goes on for 10 more moves, each with its explanation.
chessGM