Classical Variation

The Classical Variation, 4...Bf5, also called the Capablanca Variation, is the traditional way of handling the Caro-Kann after 3. Nc3 or 3. Nd2 dxe4 4. Nxe4. Black brings the light-squared bishop out before ...e6 closes it in, hitting the centralized knight at once. For a long time it was seen as the most reliable treatment of the whole defense, and much of the Caro-Kann's solid reputation comes from it. ECO files it under B18, with lines featuring 7...Nd7 assigned to B19.

By far the most common reply is 5. Ng3, which gains a tempo on the bishop; after 5...Bg6 the usual plan is 6. h4, threatening to trap the bishop with h5. Black answers 6...h6, and play typically goes 7. Nf3 Nd7 8. h5 Bh7, the Spassky Variation, followed by 9. Bd3 Bxd3 10. Qxd3. White has gained kingside space and fixed Black's pawns there, but the h5-pawn is a long-term commitment that can turn into a target once the queens come off. Black's structure is free of weaknesses, and the standard counterplay is a well-timed ...c5 to challenge d4. White frequently castles long, as in the Lobron System, 10...e6 11. Bd2 Ngf6 12. O-O-O Be7, and the Seirawan Variation, which reaches a similar setup by 10...Ngf6 11. Bd2 e6 12. O-O-O Bd6, placing the bishop more actively.

The character of the game depends heavily on where Black's king goes. Lines with Black also castling queenside earned the opening a name for being dependable but dry, whereas more recent treatments with kingside castling, or with the king left in the center, lead to sharper play; when the kings end up on opposite wings, White's attacking chances become real. At move six White can also deviate with the Maróczy Attack, 6. f4, or the Flohr Variation, 6. Nh3, both far less common than 6. h4.

Among fifth-move alternatives, 5. Ng5 is the second most popular choice and gives White comparatively good results in the Lichess database, while 5. Bd3, offering to trade the light-squared bishops, scores slightly better for Black. Engines also consider 5. Nc5 and 5. Qf3. Overall results are close to even with a small edge for White, and the engine rates the position as roughly balanced.