4.Bd2 a5: the Wade-Smyslov line is variation 3 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. Bd2 a5 …. Black keeps the bishop on b4 with 4...a5. If White takes it, the a-pawn recaptures and the a-rook wakes up. After ...d6 the bishop has no way back, so Black trades it on d2 before playing ...Nbd7. 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... a5 – Black keeps the bishop on b4. If White takes it, the a-pawn takes back and opens the a-file.
5. g3 – The most common reply. White fianchettoes.
5... O-O – Black castles first.
6. Bg2 – The bishop goes to g2.
6... d6 – Black prepares e5.
7. O-O – White castles. Now the b4 bishop needs care.
7... Bxd2 – Black trades the bishop now. The pawn on d6 blocks its way back, so it could get trapped.
8. Nbxd2 – White takes back with the knight.
8... Nbd7 – The knight supports e5.
The lesson goes on for 4 more moves, each with its explanation.
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