C40-C49 King's knight opening

├── 1. e4 e5 2. Nf3 Nf6 3. d4 Nxe4 4. dxe5 - Petrov's Defense: Modern Attack (0)
├── C40 - 1. e4 e5 2. Nf3 Bc5 - King's Pawn Game: Busch-Gass Gambit (0)
├── C40 - 1. e4 e5 2. Nf3 Nf6 3. d4 exd4 4. e5 - Petrov's Defense: Modern Attack, Center Attack (0)
├── C41 - 1. e4 d6 2. d4 Nf6 3. Nc3 e5 4. Nf3 Nbd7 - Philidor Defense: Lion Variation (11)
├── C41 - 1. e4 e5 2. Nf3 d6 - Philidor Defense (4)
├── C42 – 1. e4 e5 2. Nf3 Nf6 – Petrov’s Defense xx (79)
├── C43 - 1. e4 e5 2. Bc4 Nf6 3. d4 exd4 4.... - Bishop's Opening (18)
├── C43 - 1. e4 e5 2. Nf3 Nf6 3. d4 - Petrov's Defense: Modern Attack (22)
├── C44 - 1. e4 e5 2. Nf3 Nc6 - King's Knight Opening: Normal Variation (20)
├── C45 - 1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4.... - Scotch Game (28)
├── C46 - 1. e4 e5 2. Nf3 Nc6 3. Nc3 - Three Knights Opening (2)
├── C47 - 1. e4 e5 2. Nc3 Nf6 3. g3 d5 4. exd5 Nxd5 - Four Knights Game: Glek System (2)
├── C47 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. ....Four knights, Scotch variation (49)
├── C48 - 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 - Four Knights Game: Spanish Variation (20)
└── C49 - 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. Bb5 Bb4 - Four Knights Game: Spanish Variation, Double Spanish (8)