Main Line

The position after 4. Nxe4 is the traditional way of handling the Caro-Kann Defense, and it arises from both 3. Nc3 and 3. Nd2. The knight move to d2 reaches the same place while sidestepping some of Black's alternatives; for instance, it can answer 3...g6 with 4. c3. By capturing on e4, Black gives up the d5 strongpoint in exchange for a clear position with no structural weaknesses. White keeps the d4-pawn against Black's c6-pawn, both the d- and e-files are half-open, and White's extra space is modest. The centralized knight on e4 gives Black a target for gaining time, whether by challenging it with a knight or by developing the queen's bishop with tempo on f5.

4...Nf6 is the most common reply in the Lichess database. It offers a knight trade at once. After 5. Nxf6+, the choice of recapture shapes the game. 5...exf6, the Tartakower or Korchnoi Variation, accepts doubled f-pawns in return for quick development and open lines for the dark-squared bishop. 5...gxf6, the Bronstein–Larsen Variation, opens the g-file and is the riskier option because of the loosened kingside.

The Classical Variation, 4...Bf5, is also known as the Capablanca Variation and is the second most popular choice. Its standard course, 5. Ng3 Bg6 6. h4 h6 7. Nf3 Nd7 8. h5 Bh7, shows how the play is organized. White uses the h-pawn to chase the bishop and gain kingside space, while the bishop stays on the h7–b1 diagonal, first from g6 and then from h7. Black's main worry is the advanced h5-pawn, and the ...h6 and ...Nd7 setup is designed to absorb it.

4...Nd7 is the Karpov Variation, also called the Smyslov Variation. It prepares ...Ngf6 so that a trade on f6 can be met by a knight recapture, which leaves the pawn structure intact, as in 5. Nf3 Ngf6 6. Nxf6+ Nxf6. The cost is time, since the d7-knight must move again before the c8-bishop can come out. White's principal way to avoid the simplifying exchange is 5. Ng5. Other fourth moves are rare; the most notable is 4...h6, the Finnish Variation.

The line is one of the more frequently reached named positions. In online games White scores slightly better than Black, and draws are uncommon. Engines regard the position as close to balanced, and their top choices match the three main replies.