Scotch Game, Classical Variation

The Classical Variation appears when White advances the d-pawn to d4, Black captures it, and White's knight recaptures on d4. Black then moves the f8-bishop to c5, written 4...Bc5. This brings a piece out from its starting square and attacks the central knight in one move, so White must defend it, move it, or simplify by exchanging pieces and reducing the complexity.

An important reply is for the d4-knight to capture the knight on c6, written 5.Nxc6. If Black recaptures with the b7-pawn, Black has two pawns on the c-file, known as doubled pawns. They can be weak because one pawn may obstruct the other, but the recapture also leaves Black a half-open b-file: Black has no pawn on that file, so a rook can pressure White's b2-pawn. In other lines, Black's queen may move to h4 or f6 and add pressure against f2, a pawn initially protected only by the king.

The word Classical does not mean the game will be quiet. The center is already open because central pawns have been exchanged, giving the pieces more lines. A developing move can therefore create immediate threats. The Mieses Variation chooses 4...Nf6 and attacks e4, while the Göring Gambit takes a different approach by offering material with 4.c3.