A04-A40

Colle System

3 named lines in this family, ECO A04-A40. Under each line you get its moves and the sentences it adds that this page has not already printed. A line's own page carries up to its first 4 per-move notes in full.

Rhamphorhynchus VariationA04

1. Nf3 c5 2. e3 g6 3. d4 Bg7 4. dxc5 Qa5+

An early pawn trade leaves the c-file as Black's avenue and the d-file as White's - both sides get real winning chances down their own file. White is up material out of the opening - Black is banking on activity to show for it. Black's kingside bishop takes the long diagonal. White develops with Nf3, e3, Bd3, c3, and 0-0, then plays for the e3-e4 break to free the position.

1. Nf3 Develops the knight to f3, eyeing d4 and e5. Theory calls this the Zukertort Opening.
1... c5 Fights for d4 from the flank - contesting the centre without committing a centre pawn. Theory calls this the Sicilian Invitation.
2. e3 Supports the centre, adding control of d4.
2... g6 Prepares the fianchetto: the bishop will take the long diagonal via g7.

Pterodactyl VariationA40

1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 Qa5+

1. d4 Stakes a claim in the centre, controlling e5, and frees the bishop and queen.
1... g6 Theory calls this the Modern Defense.
2. Nf3 It also props up the d4 pawn.
2... Bg7 Fianchettoes the bishop onto the long diagonal, pressuring d4 and e5 from a distance.

Siroccopteryx VariationA40

1. d4 g6 2. Nf3 Bg7 3. e3 c5 4. Bd3 cxd4 5. Nxd4 Qa5+

Walk these lines on a board

An account opens every move's note in this family, the plan behind each line, and a trainer that plays the line back at you. It is free.

Create account All families