ECO C2 Double King Pawns

C20 - Double King Pawn Opening 
1. e4 e5

C21 - Centre Game/Danish Gambit
1. e4 e5   
2. d4 ed4

C22 - Centre Game
1. e4 e5   
2. d4 ed4  
3. Qd4 Nc6

C23 - Bishop's Opening
1. e4 e5    
2. Bc4

C24
1. e4 e5    
2. Bc4 Nf6

C25 - Vienna Game
1. e4 e5   
2. Nc3

C26
1. e4 e5   
2. Nc3 Nf6

C27 - Vienna Game, Frankenstein-Dracula Variation
1. e4 e5   
2. Nc3 Nf6   
3. Bc4 Ne4

C28 - Vienna Game
1. e4 e5   
2. Nc3 Nf6   
3. Bc4 Nc6

C29 - Vienna Gambit
1. e4 e5   
2. Nc3 Nf6   
3. f4 d5

ECO chess codes