King Expose: Ruy Lopez (Spanish Opening) line

Engine-verified opening line.

1. e4
2. e5
3. Nf3
4. Nc6
5. Bb5
6. Nf6
7. O-O
8. d6
9. Re1
10. Be7
11. c3
12. O-O
13. d4
14. exd4
15. cxd4
16. Bg4
17. Nc3
18. Bxf3
19. gxf3
20. a6
21. Bf1