Originally posted by badivan1
I was wondering why in the Classical KID 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 people play 5.Be2 instead of 5.Nf3. Anyone who can explains this?
Good question. Looking at that board set-up without knowing anything about the theory of the opening, I can make a list of things 5.Be2 accomplishes which 5.Nf3 does not:
(1) The queen and bishop now control the squares g4 and h5, preventing the Black bishop and knight from occupying them.
(2) The White king has additional cover on the e-file.
(3) The f3 square is available for a pawn, and a pawn on f3 may prepare a kingside pawnstorm because it in turn facilitates g4, depending on how Black plays. The queen/bishop battery on the aforementioned diagonal may be relevant here also. Looking at the databases, in some lines White eventually plays Nf3 anyway, but delaying the deployment of the knight may give White more flexibility to consider an early attack.
That's my guess.