ECO A28
6 named openings and variations are classified as A28. ECO (Encyclopaedia of Chess Openings) codes group openings from A00 to E99 by their opening moves.
- English Opening: Four Knights System, Nimzowitsch VariationA281. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. e4
- English Opening: King's English Variation, Four Knights VariationA281. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6
- English Opening: King's English Variation, Four Knights Variation, Bradley Beach VariationA281. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. d4 e4
- English Opening: King's English Variation, Four Knights Variation, Flexible LineA281. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. d3
- English Opening: King's English Variation, Four Knights Variation, Korchnoi LineA281. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. a3
- English Opening: King's English Variation, Four Knights Variation, Quiet LineA281. c4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. e3