The Four Knights Variation, American Attack is a variation of the Sicilian Defense, catalogued as ECO B45. The line runs 1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nc3 Nf6 6. Ndb5 Bb4 7. Nd6+, reaching the position shown below after 13 half-moves.
White holds the centre with pawns on e4. Development is level at two minor pieces each. It is Black to move after seven moves.
On the Sicilian Defense generally: The most popular and aggressive response to 1.e4. Black fights for the center asymmetrically, leading to rich tactical play.
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The Four Knights Variation, American Attack goes 1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nc3 Nf6 6. Ndb5 Bb4 7. Nd6+. It is a variation of the Sicilian Defense and is catalogued as ECO B45.
The Four Knights Variation, American Attack is ECO B45. ECO codes group openings by their move order, so nearby codes cover closely related lines of the Sicilian Defense.
Stockfish evaluates the position after 1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nc3 Nf6 6. Ndb5 Bb4 7. Nd6+ at +0.16 at depth 18, which is balanced. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
White holds the centre with pawns on e4. Development is level at two minor pieces each. It is Black to move.