Ruy Lopez Open Variation. I use this in over the board chess and have prepared it to a certain extent. Most games follow the next few moves until white's ninth where a number of options have been tried in master chess.

The Keres Variation

I've not tried this before. Given as "simplest" in Gerald Abraham's "The Chess Mind" in notes to a diagram about 9.Qe2 in the chapter about memory. As far as I can tell it was a suggestion that has lain buried or never caught on at master level. It does not appear in either of my single volume opening books.

Black begins to push the Q - side pawn majority. I did have to consider lines like Ne1 and f3 where White tries to embarrass the knight on e4.

But this way it is easier...

I feel sure these exchanges play into Black's hands as they do not halt the advance of the queenside majority.

The bishop does look worse than the knight but after Nxe6 fxe6 white can prepare f4 and perhaps advance his own pawn majority. White probably feared the open f file but I am not sure it was that critical.

Offering the a pawn but after Bxa2 b3 is very strong. Black has to be careful about the Q on the same file as the rook...

Threat: winning a pawn with cxd4.

Simple defence. Black can now take over the d file, show the weakness of the white first rank and pick up the a pawn safely as b1 becomes a safe escape square for the bishop.