The theory of key squares

I have developed a theory that in all openings there are certain key squares around which the fight revolves and on which the outcome of the game can depend. Of course as these key squares are obtained or sacrificed new key squares develop and the process goes on. But in the opening, for these openings I have found that these are the key squares

1. French Defense - c5(which black controls thanks to the bishop on f8 and the queen on b6) and d4(which black wants to control through the c5 pawn and if the pawn is exchanged through BXc5), e5(later in the game when black makes his dream pawn break of f6 obtaining the center for good and securing the game)

2.King's indian defense - g4(the crucial pawn break for black, supported by h5 and the c8 bishop and either rook on g8 or N on f6) and d6(the backward black pawn which white attacks through b4 and c5)

3. Ruy Lopez - d4(which black tries to control through c3), e4(which white controls and which black attacks either by Bb7 or by exerting pressure with the e8 rook after exchanging off on d4)

4.Sicilian Najdorf - c4(which black wants to control through b5 as well as routing the light colored bishop through e6 to c4 and the knight routed through Nbd7-Nb6-Nc4) and Rc8

Similarly, there are always key squares which both sides try to fight for. I believe that instead of learning the moves, people should try and focus on key squares and this makes the moves seem logical.

This can be carried throughout the game as new key squares develop. Frequently, open files and diagonals are important in open games but key squares are important when the position is closed.