Home › Openings › Grünfeld Defense › Grünfeld Defense: Three Knights Variation Grünfeld Defense: Three Knights Variation, Petrosian System ECO D91 · 1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. Nf3 Bg7 5. Bg5 Related variationsGrünfeld Defense: Three Knights Variation, Burille VariationGrünfeld Defense: Three Knights Variation, Hungarian AttackGrünfeld Defense: Three Knights Variation, Hungarian VariationGrünfeld Defense: Three Knights Variation, Paris VariationGrünfeld Defense: Three Knights Variation, Vienna Variation Practice this opening · Play against the computer