The Main Line is a variation of the King's Indian Attack, with Bf5, catalogued as ECO A07. The line runs 1. Nf3 Nf6 2. g3 d5 3. Bg2 c6 4. O-O Bf5 5. d3 h6 6. c4 dxc4, reaching the position shown below after 12 half-moves.
The four central squares are empty of pawns, so the fight for them is being conducted by pieces, and one pawn capture is available, so the structure has not settled yet. Development is level at two minor pieces each, and Black is up a pawn of material. It is White to move after six moves. White has castled while Black’s king is still uncommitted; Black has doubled pawns on the c-file.
On the King's Indian Attack, with Bf5 generally: ECO A07. A chess opening with 3 known variations.
You can play through this variation move by move in your browser — Learn mode walks the line with an explanation at each step, and Drill mode replays it from memory so you find out whether you actually know it. No account is required.
See all 4 King's Indian Attack, with Bf5 variations →
The Main Line goes 1. Nf3 Nf6 2. g3 d5 3. Bg2 c6 4. O-O Bf5 5. d3 h6 6. c4 dxc4. It is a variation of the King's Indian Attack, with Bf5 and is catalogued as ECO A07.
The Main Line is ECO A07. ECO codes group openings by their move order, so nearby codes cover closely related lines of the King's Indian Attack, with Bf5.
Stockfish evaluates the position after 1. Nf3 Nf6 2. g3 d5 3. Bg2 c6 4. O-O Bf5 5. d3 h6 6. c4 dxc4 at +0.43 at depth 18, which is a slight pull for White, within normal opening margins. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
The four central squares are empty of pawns, so the fight for them is being conducted by pieces, and one pawn capture is available, so the structure has not settled yet. Development is level at two minor pieces each, and Black is up a pawn of material. It is White to move. White has castled while Black’s king is still uncommitted; Black has doubled pawns on the c-file.