Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...a6/4. Ba4/4...Nf6/5. O-O/5...Be7/6. Re1/6...b5/7. Bb3/7...d6

=Ruy Lopez Main Line=

Whenever White opens with 1. e4, her most reliable plan is then to prepare to play d4. There is a very good reason not to play 8. d4? instantly - click and learn.

Instead, it must be prepared with 8. c3. With White's kingside fully developed there is no reason to delay this useful move any longer.

Note that h3 will be a useful move, but not yet - because it turns out that 8. c3 is also necessary to give the b3-bishop a retreat square. A White player who forgets her move order and plays 8. h3 is liable to have her bishop confiscated with 8...Na5.