Accelerated Gurgenidze

The Accelerated Gurgenidze arises from the Modern Defense move order 1. e4 g6 2. d4 d6 3. Nc3 c6. It is classified under B06 and grouped with the Rat Defense. The name links it to the Gurgenidze system of the Caro-Kann, which comes about after 2...c6 3. Nc3 d5. Here Black has already spent a tempo on ...d6, which covers e5 and stops White from gaining space with e4-e5. The early ...c6 holds back the fianchetto and leaves Black's plans open. The c-pawn can support a queenside expansion with ...b5, or a later central challenge, and Black does not yet commit the king's knight or bishop.

White keeps the two-pawn center and chooses how to use it. The most common reply is 4. Nf3, a quiet developing move. The sharper alternatives are 4. f4, which grabs kingside space, and 4. Be3. Engines also suggest 4. h3 and 4. Bc4, and they assess the position as a slight edge for White. In practice the results are close to even and draws are rare, which points to unbalanced, fighting games.