How Much Theory in the Open Ruy Lopez?

I mean, how often is the Open Variation played these days?

I'm asking because in looking over Andrew Greet's book on the Worrall System for the Spanish he recommends using the move order 5. Qe2 rather than 6. Qe2.  (i.e. 1. e4 e5  2. Nf3 Nc6  3. Bb5 a6  4. Ba4 Nf6  5. Qe2 rather than  1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6  5. 0-0 Be7  6. Qe2)

OK, so on the surface the idea to play 5. Qe2 to avoid the Open seems sound.  But if you play 5. Qe2 then Black's dark squared bishop isn't yet committed and Black now has several variations to choose from including 5...Bc5 which Greet states is the most difficult for White to handle.

Now, I'm not going to pretend like I am an expert on this opening.  I have never played it OTB, and I have rarely studied it at all.  But I'm wondering where White gets the most bang for his buck...by avoiding the Open Spanish or by avoiding the 5...Bc5 Worrall?

Thoughts?

There is more theory behind the Ruy Lopez than any other opening. Some variations go 25-40 moves deep.

For some that is an entire game.

I don't think Qe2 gives white much anyway, but if you want to play it, go for it on move 6 and allow the Open Spanish. Just pick one line against the Open and wait until the B is on e7. That way you can also switch later from 6. Qe2 to the 6.Re1 main lines or 6.d3, which is getting more and more popular. By the way, also 5.d3 can be considered, which has the same drawback as 5.Qe2, allowing Bc5. Waiting for the B to go to e7 is beneficial in both cases.

Thank you.  By the way, I really enjoy your YouTube videos.

In the 1970s, Viktor Korchnoi wrote the ECO section on the Open Spanish. He then was beaten by Karpov and the line kinda died down for a while. Now, there's a new Grandmaster Repertoire book on the Open Spanish. 

There's quite a bit of theory on the Open Spanish now. Which is good and bad news for players interested in trying it. 

I think it's awesome that there is a Grandmaster Repertoire book on the Open Spanish for two reasons...

a) That series is extremely high quality and well written.  I have the books on the Caro-Kann, the Sicilian, and Volume One of the English.

b) Hopefully this means that players at the club level will play the Open more often.   I'm hoping that because if true then the 5. Qe2 move order will play right into my hands against that particular subset of players.