Problem

I would move the knight to d4 , now  black has a better position and takes control .

Would you like to play this in a game ?

you could do the same with your black bishop

It's the Spanish 4 Knights. a6 is alright (With same play as in Ruy Lopez).

Reuben Fine's book: "The Ideas Behind the Chess Openings" (An extremely good book on the Opening, by the way.) suggests the following move order for Black after 4.Bb5 

The great thing about this line is that White simply can't accept the pawn! Here's why:

If White refuses the gambit by Bc4, then:

If White simply tries to develop after Black's Gmabit, then he will not retain the advantage:

Another development try for White:

All told, this line offers good chances for Black, and I use it the most in my Four Knights games.

the problem with that is, daniel3, that if white captures the knight, instead of the pawn, white is much further in development. 

Sine 5.Nxd4 is not given aa a theoretically sound move for White, I'm inclined to believe that it has been tried before, but hasn't had much success. After 5.Nxd4 exd4, White's knight must move again; losing tempo that is crucial to development. Black will also carry the upper hand in the centre.

 Daniel , you are right that perhaps 5 Nxd4 might not be theoretically sound but it is given by theory, however it scores less than 50% for white and thats not acceptable to most players. You are wong however that after 5Nxd4 exd4 that the knight must move again as the main line goes 6 e5 after that. What sources do you use for your "theory" ? 

All the lines I have given are taken from Reuben Fine's book "The Ideas Behind the Chess Openings." I didn't consider the possibility of e5, but I thought that since these moves weren't given in a book written by a master at openings, they must have some flaw in them somewhere.

i think these variations should be categorized as opening

traps not cllasical openings please let me know more

                                                           thank you

nice !!!

The book you have by Fine is an excellent book and was one of my earliest books. However, I just checked and now cant find it anywhere ......  One of the down sides of loaning books out, sometimes you dont get them back. I checked chess assistant and what scores best for white after 4...Nd4 is 5 Ba4 with white scoring 57%  based on 798 games in my database.

5.Ba4 is also listed in Fine's book; and the line that he considers best against it is:

Likewise on the normal 7.O-O, 7...d6 or even 7...d5. The point is that White must not be allowed to develop properly:

The Reubinstein Defence still continues to be a popular choice against White's bishop move. I consider it to be extremely strong for Black.