ECO chess codes A5 (idea)

A50 - Indian systems with 2. c4
1. d4 Nf6   
2. c4

A51 - Budapest Gambit 
1. d4 Nf6   
2. c4 e5

A52 - Budapest Gambit Accepted
1. d4 Nf6   
2. c4 e5   
3. de5 Ng4

A53 - Old Indian Defence 
1. d4 Nf6   
2. c4 d6

A54 
1. d4 Nf6   
2. c4 d6   
3. Nc3 e5   
4. Nf3

A55 
1. d4 Nf6   
2. c4 d6   
3. Nc3 e5   
4. Nf3 Nbd7    
5. e4

A56 - Benoni Defence 
1. d4 Nf6   
2. c4 c5

A57 - Benko Gambit 
1. d4 Nf6   
2. c4 c5   
3. d5 b5

A58 - Benko Gambit Accepted 
1. d4 Nf6   
2. c4 c5   
3. d5 b5   
4. cb5 a6   
5. ba6 

A59 - Benko Gambit Accepted/Classical Variation
1. d4 Nf6   
2. c4 c5   
3. d5 b5   
4. cb5 a6   
5. ba6 Ba6   
6. Nc3 d6 
7. e4 

ECO Chess Codes
Chess Notation
Chess Openings