3...g6: the fianchetto is variation 4 of 5 in the Stonewall Attack course, a beginner opening course for White (ECO D00). It runs 23 moves and begins 1. d4 d5 2. e3 Nf6 3. Bd3 g6 4. f4 Bg7 …. Black puts the bishop on g7, which protects the king well. White still builds the wall, trades the knight for Black's light bishop and attacks with the g-pawn. 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... d5 – Black meets it.
2. e3 – The Stonewall start.
2... Nf6 – Black develops.
3. Bd3 – The bishop aims at h7.
3... g6 – Black gets ready to put the bishop on g7. This protects the king well.
4. f4 – White still builds the wall. The pawn on f4 controls e5.
4... Bg7 – The bishop goes to g7.
5. Nf3 – The knight develops and heads for e5.
5... O-O – Black castles.
6. O-O – White castles too.
6... c5 – Black hits the centre from the side.
7. c3 – White holds d4 and completes the wall.
7... Nc6 – Black adds pressure on d4.
8. Nbd2 – The second knight develops and watches e4.
8... Bg4 – The bishop pins the f3 knight to the queen.
The lesson goes on for 7 more moves, each with its explanation.
chessGM