C47: Four knights, Scotch, Krause variation

C47 Sub-variants:

• Four knights, Scotch variation
  1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4
• Four knights, Scotch, Krause variation
  1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 Bb4 5. Nxe5
• Four knights, Scotch, 4...exd4
  1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 exd4
• Four knights, Belgrade gambit
  1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 exd4 5. Nd5