Exchange Variation, Classical Variation

With 7. Bc4, White puts the light-squared bishop on an active diagonal before developing the king's knight. That order has a price. Once the bishop stands on c4, an ordinary Nf3 lets ...Bg4 bear down heavily on d4. The knight therefore normally goes to e2, or White plays Nf3 together with h3. In this scheme the bishop is the more active minor piece, whereas in the Modern 7. Nf3 system the knight is. White's usual plan is O-O followed by f4–f5, aiming either to break through in the center or to attack the black king. Black works against d4 with ...c5, ...Nc6, ...Bg4 and often ...cxd4 or ...Qa5.

About two thirds of games continue 7...c5, the gateway to the Spassky line, 8. Ne2 O-O, and to the Seville Variation. Most of the remainder start with 7...O-O. The engine considers the position roughly balanced. Results on Lichess are close to even, with very few draws, which reflects the sharp, double-edged play.