2.c4 c6 3.e3: the bishop goes to g4 is variation 1 of 6 in the Against the Réti and King's Indian Attack course, a intermediate opening course for Black (ECO A11). It runs 20 moves and begins 1. Nf3 d5 2. c4 c6 3. e3 Nf6 4. Nc3 Bg4 …. Black protects d5 with 2...c6 and develops the bishop to g4 before playing ...e6. After the trade on f3 Black builds a solid chain from c6 to e6. Then Black castles and prepares the e5 break. In the lesson every move is explained on a board and then drilled; it is free.
Move by move
1. Nf3 – White develops a knight and keeps every plan open.
1... d5 – Black takes a share of the centre at once.
2. c4 – The Réti Opening. White attacks the d5 pawn from the side.
2... c6 – Black protects d5 with a pawn. This is the solid Slav set-up.
3. e3 – White opens the f1 bishop and keeps the d4 push for later.
3... Nf6 – Black develops and adds a guard to d5.
4. Nc3 – White develops and adds pressure on d5.
4... Bg4 – Black pins the knight before White plays d4. The bishop develops outside the pawn chain.
5. h3 – White asks the bishop to decide at once.
5... Bxf3 – Black gives the bishop for the knight. White has to take back with the queen.
6. Qxf3 – White takes back and keeps a healthy pawn structure.
6... e6 – Black builds a strong chain from c6 to e6. Now the f8 bishop can develop.
7. d4 – White claims the centre.
7... Nbd7 – The knight develops and supports a later push to e5.
8. Bd3 – White develops and aims the bishop at the kingside.
8... Bb4 – The bishop pins the c3 knight and makes the e4 push harder.
The lesson goes on for 4 more moves, each with its explanation.