Classical 4.Qc2: ...O-O, ...Bxc3+ and ...b6 is variation 2 of 6 in the Nimzo-Indian Defence course, a advanced opening course for Black (ECO E32). It runs 26 moves and begins 1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 O-O …. White avoids doubled pawns by recapturing on c3 with the queen. Black fianchettoes the queen's bishop, then breaks with ...d5; in the main line Black even trades queens with a neat ...Nxc3 trick. 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 stops e4.
2. c4 – White gains space on the queenside.
2... e6 – Prepares ...Bb4 and ...d5.
3. Nc3 – White prepares e4.
3... Bb4 – Pins the knight and fights for e4.
4. Qc2 – The Classical: White's queen guards c3 so that ...Bxc3+ can be met by Qxc3 without doubled pawns, and it also controls e4.
4... O-O – Black castles and waits to see White's plan; the king is safe long before White's.
5. a3 – White forces Black to take on c3, gaining the bishop pair.
5... Bxc3+ – Black takes now; White has no doubled pawns but has spent many queen and pawn moves.
6. Qxc3 – White recaptures with the queen and keeps a healthy pawn structure.
6... b6 – Black fianchettoes the c8-bishop to control e4 and the long diagonal.
7. Bg5 – White pins the f6-knight, which is Black's main defender of e4 and d5.
7... Bb7 – The bishop joins the fight for e4 along the long diagonal.
8. f3 – White controls e4 with a pawn so Black's pieces cannot use it, and prepares e4 later.
8... h6 – Black asks the bishop to decide: give up the bishop pair on f6 or retreat to h4.
The lesson goes on for 10 more moves, each with its explanation.
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