Grünfeld Defense, Three Knights Variation

The Three Knights Variation is named because White has developed both knights, moving them from their starting squares to c3 and f3, while Black has a knight on f6. Coordinates such as c3 name a square by its file and rank. The name counts those three developed knights. It does not imply an extra piece or require the fourth knight to remain unmoved.

Developing White's g1-knight to f3 reinforces the center and prepares castling, the special move that relocates the king and a rook together to improve king safety. Black keeps the main Grünfeld idea: develop the bishop to g7 and attack the d4-pawn with the c-pawn or through central pawn exchanges.

The setup is flexible because White can still develop the c1-bishop to f4, g5, or e3 and choose between a broad or restrained center. Flexibility also has a cost. If White delays the central decision too long, Black may open the position before White's pieces are coordinated. In the Brinckmann Attack, the bishop goes to f4 immediately and its role is defined earlier.