Cozio Attack

The Cozio Attack, 5. Qe2, is the Classical Variation line in which White meets 4...Nxe4 by attacking the knight at once instead of building a center with 5. d4. With the e-file cleared, the queen pins the knight against Black's king, and the threat is simply to win it with d3. Supporting the knight with 5...d5 does not help, since 6. d3 still wins the piece. The same practical problem awaits 5...Bf5, and both moves score poorly for Black. The near-universal answer is 5...Qe7, which blocks the file and protects the knight.

After 6. d3 Nf6 the queens usually come off on e7, leaving a symmetrical endgame with few imbalances. White hopes to make something of a small lead in development, but the engine sees the position as roughly balanced. The line is the most common fifth move among amateurs, partly because it sets the trap after 5...d5. At higher levels it is regarded as a route to simplification rather than an attempt to win. Even so, online games rarely end in draws, and the results between the two sides are close to even.