Piece Gain: Ruy Lopez (Spanish Opening) line

Engine-verified opening line.

1. e4
2. e5
3. Nf3
4. Nc6
5. Bb5
6. Bc5
7. c3
8. d6
9. d4
10. exd4
11. cxd4
12. Bb4+
13. Kf1
14. Bd7
15. Qa4
16. Nge7
17. d5
18. a6
19. dxc6
20. bxc6
21. Bd3