Grünfeld Defense: Three Knights Variation
1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3
In the Three Knights Variation against the Gruenfeld, White uses the move 5.Qb3 to force Black to exchange on c4, thus giving White a strong pawn center after a subsequent e2-e4.
Pros:
- White gains the strong pawn center
- Black does not get a chance to exchange a pair of knights
Cons:
- The queen moves several times
- White's center can be very exposed
- White delays the kingside development