411 REFERENCE · Wikibooks
Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...d6/4. d4
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Steinitz defence C62 Spanish game → Steinitz defence
Scotch game → 3...d6?! (by transposition, rare)
Philidor defence → 3...Nc6?! (by transposition, rare)
4. d4
White has two attackers on e5 and threatens to win it.
Black must either take the pawn first in trade, 4...exd4 5. Nxd4, or break the pin with 4...Bd7, so defending e5. In the latter continuation, Black may find themselves choosing between keeping the pawn protected and their development.
4...Nf6?!, counter-attacking e4, doesn't work out due to 5. dxe5 Nxe4 6. Qd5!, attacking the knight on e4. If Black defends well, they only lose a pawn: 6...Nc5 7. Ng5 (threatening Qxf7#) Ne6 (interposes between the queen and f7) 8. Bxc6+ bxc6 9. Qxc6+ (wins a pawn) Bd7 10. Qf3 (threatens Qxf7#) Nxg5 11. Bxg5 (trades knights)+.
Theory table
1. e4 e5 2. Nf3 Nc6 3. Bb5 d6 4. d4
4
5
...Bd7
Nc3
1
...exd4
Nxd4Bd7
1
References
See also
Ruy Lopez