Grünfeld Defense: Three Knights Variation

1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3

ECO D90

The Grünfeld Defense: Three Knights Variation is a chess opening line in the Grünfeld Defense complex, reached after 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3.

It is catalogued under code D90 in the Encyclopaedia of Chess Openings (ECO).

The defining move Nf3 is chosen by White on move 4.

6 named continuations branch from this position, including the Petrosian System and the Hungarian Attack.

Named variations

• Grünfeld Defense: Three Knights Variation, Petrosian System — ECO D91
• Grünfeld Defense: Three Knights Variation, Hungarian Attack — ECO D92
• Grünfeld Defense: Three Knights Variation, Hungarian Variation — ECO D93
• Grünfeld Defense: Three Knights Variation, Burille Variation — ECO D94
• Grünfeld Defense: Three Knights Variation, Paris Variation — ECO D94
• Grünfeld Defense: Three Knights Variation, Vienna Variation — ECO D95

Study this line with a grandmaster

This position is covered in the Grunfeld Defense course: a GM-authored repertoire you study move by move, then practice against a human-like AI opponent.

Every chess term used here is defined in the chess terms glossary. Browse all opening courses or the full ECO code index.