Queen's Gambit Declined: Queen's Knight Variation – Bb4

The core tension here is the pin on your knight at c3. Black's bishop on b4 ties your knight to the defence of the e3 pawn (since ...Bxc3+ would double your c-pawns). Your move 4.e3 has already dealt with the threat to your knight — the pawn covers d4 and protects the bishop on c1, while keeping your options open for developing the king's knight to f3. Your main objective now is to solidify the centre, complete development, and decide whether to challenge Black's bishop immediately or let it sit on b4. The engine's top pick, c5, goes straight for the throat: you attack Black's d5 pawn, force a reaction, and open lines for your pieces.

If you're looking for the single best move, Stockfish recommends 5.c5. This advance locks in the space advantage on the queenside and asks Black a blunt question: what do you do about your d5 pawn? The engine's continuation after c5 runs: Nf3 Nc6 Be2 — natural developing moves that bring your pieces to good squares while Black figures out how to handle the cramped position. Notice that you don't rush to deal with the pin on c3. Instead, you gain space and let Black decide when (and if) to capture on c3. This approach keeps the pressure on and scores solidly across thousands of games.

From 404,995 games at this exact position, the numbers tell a clear story. White wins 55.1% of the time, with only 3.9% draws and 41.0% Black wins. That win rate is healthy — you're scoring above 50% no matter which reply Black chooses. Let's look at the top responses from Black: - Nf6 (164,950 games): Black's most popular move. White scores 54.3%. Develop the knight and prepare to castle. - Bxc3+ (130,836 games): The second-most common reply. White scores 55.5%. But be warned — this is actually a mistake! - Nc6 (25,934 games): White scores 56.6% , your best result against any popular reply. - c5 (18,083 games): White scores 53.5% , a solid but slightly lower edge. - c6 (15,643 games): White scores 54.5% . - dxc4 (14,823 games): White scores a whopping 58.6% , your highest win rate across all major replies.

Black's second-most-popular move, Bxc3+, is flagged as an inaccuracy by the engine. Taking on c3 gives up the bishop pair and lets you recapture with the b-pawn (bxc3), which actually strengthens your centre — you now have a solid pawn trio on c3-d4-e3 and an open b-file for your rook. The engine says this costs Black roughly 0.6 pawns of advantage; the better move was c5, challenging your centre before committing the bishop. In practice, White scores 55.5% after Bxc3+, so you can happily welcome this exchange. Develop naturally, castle, and enjoy the bishop pair against Black's knight. If Black plays anything else — Nf6, Nc6, c6, dxc4 — you have the chance to push forward with c5 on the next move or complete development with Nf3 and Be2.