Why do white Ruy Lopez players not automatically play black Ruy Lopez?


2.Nf3 and 3.Bb5 aren't forced. Other than the Ruy, you need to know a dozen other openings to play 1.e4 e5
And even if you enter it, it doesn't really cut down study, because white isn't obligated to play the same way you do. Whether or not they play the exchange variation is probably the first major difference, for example.

But you're absolutely right that it makes a lot of sense for a Ruy Lopez player to take both sides, very efficient.

But the black side of 1. e4 e5
really should be a major option for a Ruy Lopez player.
The other king pawn openings are just not as testing. You should be happy to play the black side of the Kings Gambit, for instance.

Whatever opening repertoire you chose, there are quite a lot variations you need to consider. So why not go with the statisticly most prominent? I have never played the Ruy as defense. But I'm going to try it out and see if I gain an advantage by playing it with both colours. Any comments by "dual" players very welcome.

When I was 1700-2100 I loved my black openings and knew them well. I had nothing much for white.
I opened with 1. a3 so I could try to be black every game.

When I was 1700-2100 I loved my black openings and knew them well. I had nothing much for white.
I opened with 1. a3 so I could try to be black every game.
What did you do after 1.a3 a6? lol

When I was 1700-2100 I loved my black openings and knew them well. I had nothing much for white.
I opened with 1. a3 so I could try to be black every game.
What did you do after 1.a3 a6? lol
No one ever did that. Nice try but you missed the point.

How does opening 1. a3 mean you get to be black?
Black gets to choose the course of the opening. He gets to choose how to occupy the center, with a c, d, e pawn. This is usually the main advantage of playing white.

How does opening 1. a3 mean you get to be black?
There's an exploit. When programming chess, the way they have it process the color and file of the destination square means if your first move is to a dark square on the a file, it actually swaps the colors of the pieces. It doesn't work when playing Na3 because piece moves are handled differently. This only works on the first move, because the program treats that as move zero.
This was a common way to get to move twice back when you could request a takeback. What you'd do is ask for a takeback then immediately play 1.a3. You become black and accept the takeback. The program then resets the position back to the start, and thinks you get two moves. One because of the takeback (even though you're black now) and 1 because it thinks it's black's move.
That's why you see some old games beginning with 1... e5 and 2...d5 and white gets his first move on move 3.
What does it mean to choose "the Ruy as a defense"? After 1 e4 e5 2 Nf3 Nc6 3 Bb5 a6 4 Ba4 Nf6, White does not usually play 5 Nc3. As it happens, after 1 e4 e5 2 Nf3 Nc6 3 Nc3 Nf6 4 Bb5, a standard reply is 4...Bb4.

How does opening 1. a3 mean you get to be black?
There's an exploit. When programming chess, the way they have it process the color and file of the destination square means if your first move is to a dark square on the a file, it actually swaps the colors of the pieces. It doesn't work when playing Na3 because piece moves are handled differently. This only works on the first move, because the program treats that as move zero.
This was a common way to get to move twice back when you could request a takeback. What you'd do is ask for a takeback then immediately play 1.a3. You become black and accept the takeback. The program then resets the position back to the start, and thinks you get two moves. One because of the takeback (even though you're black now) and 1 because it thinks it's black's move.
That's why you see some old games beginning with 1... e5 and 2...d5 and white gets his first move on move 3.
This is also why the 1984 Karpov - Kasparov match was halted. Kasparov started winning because he was getting two first moves.