ENCYCLOPAEDIA OF CHESS OPENINGS
»ECO Code« is a trademark of Chess Informant Inc.

ECO
B0

ECO
B1

ECO
B2

ECO
B3

ECO
B4

1. e4 c6

1. e4 c5

1. e4 c5
2. Nf3 Nc6

1. e4 c5
2. Nf3 e6

without 1... c6,
1... c5, 1... e6,
1... e5

without 2. Nf3

2. Nf3 without
2... Nc6, 2... e6,
2... d6

ECO
B5

ECO
B6

ECO
B7

ECO
B8

ECO
B9

1. e4 c5 2. Nf3 d6 3. d4 cd4

1. e4 c5 2. Nf3 d6 3. d4 cd4

1. e4 c5 2. Nf3 d6 3. d4 cd4

1. e4 c5 2. Nf3 d6 3. d4 cd4

without 3. d4

4. Nd4 Nf6
5. Nc3 Nc6 6. Bg5

4. Nd4 Nf6
5. Nc3 g6

4. Nd4 Nf6
5. Nc3 e6

4. Nd4 Nf6
5. Nc3 a6

3. d4 without
3... cd4

3... cd4 without
4. Nd4

4. Nd4 without
4... Nf6

4... Nf6 without
5. Nc3

5. Nc3 without 5... Nc6, 5... g6, 5...e6, 5... a6

5... Nc6 without
6. Bg5