Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nf6/5. O-O/5...Nxe4/6. d4/6...b5/7. Bb3

=Ruy Lopez Open Defence=

Black must skirt a couple of pitfalls here. 7...Na5 (intending 8. Bd5 Bb7 and the pulverisation of White's light-squared bishop) walks into 8. Bxf7+! Kxf7 9. Nxe5+ Kg8 10. Qf3, while the greedy 7...Nxd4 is refuted by the greedier 8. Nxd4 exd4 9. Bd5.

But in truth Black should be in no danger of falling into either trap, because her arm should shoot out and play 7...d5! of its own accord. When Black has already played ...e5, ...d5 is almost always a fine move, and here it fortifies the e4-knight, limits the scope of the b3-bishop and actually allows some flexibility in the development of the back rank, a luxury hardly ever afforded to Black.

By contrast 7...Be7 is as insipid now as it was on move 6. Play the most useful moves first!

7...exd4?! allows 8. Re1 d5 9. Nc3! and Black can choose between 9...dxc3 10. Bxd5 and 9...Be6 10. Nxe4 dxe4 11. Rxe4 Be7 12. Bxe6 fxe6 13. Nxd4 followed by 14. Qg4, White having a large initiative in either case.

Theory table
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1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Nxe4 6. d4 b5 7. Bb3