Queen's Pawn Game: London System: c5 — A Dead-Level Test of Your Understanding

The London System usually lets White build a safe, solid centre. But after 3...c5, Black is saying: 'I'm not letting you have that space for free.' By playing 4.c3, you protect the d4-pawn and keep the centre closed — for now. The whole middlegame hinges on whether Black can successfully undermine d4 or whether you can maintain it and eventually push e3-e4. There's no grand attack coming; this is a patient, positional battle where one pawn break decides the game. The statistics show just how balanced this is: you're not better, but you're not worse either. Every move counts.

Stockfish's top choice for Black here is Qb6 — a queen move that attacks b2 and eyes the d4-pawn. The full recommendation continues Qb6 Qc2 Nc6 dxc5, after which Black recaptures and the centre dissolves. That line scores only 44.4% for White across 21,737 games, so it's worth knowing. If Black plays Qb6, your reply should be Qc2, protecting b2 and keeping the d4-pawn defended. Be ready to release the tension with dxc5 if needed; the resulting position is still balanced if you develop naturally.

Here are Black's most common moves in the position after 4.c3, with how White scores against each. The numbers reveal who knows the opening — and who doesn't. - Nc6 (130,934 games): The most popular by far. White scores just 46.3% — so Black gets good play by developing naturally. - e6 (41,654 games): Black solidifies the centre. White scores 50.6% here, your best chance to outperform the average. - cxd4 (21,696 games): Black trades immediately. White scores 48.4% — fine, but nothing special. - Bf5 (14,731 games): White scores 50.0% — and this is actually a mistake. - Bg4 (10,421 games): White scores 50.5% — another inaccuracy for Black to avoid.

The statistics flag two moves as clear inaccuracies for Black: Bf5 and Bg4. If your opponent plays either one, you have a real chance to seize a small advantage. - Bf5 loses roughly 0.5 pawns of evaluation compared to the best move Qb6. Why? The bishop looks active but becomes a target after e3-e4. Black should instead have probed your centre with Qb6. - Bg4 is worse, losing about 0.8 pawns. Pinning the knight on f3 might seem natural, but it wastes time and lets you chase the bishop with h2-h3, gaining a tempo. Your score against both of these moves is around 50% — meaning club players often let the advantage slip. Don't be one of them. When you see Bf5 or Bg4, ask yourself: 'How can I make that misplaced bishop regret its choice?'

Because this line is so balanced, the middlegame you reach will depend entirely on Black's choice. If Black plays Nc6 or e6, expect a slow, manoeuvring struggle where piece placement and the e3-e4 break decide everything. If Black plays cxd4, you recapture with cxd4 and get an isolated queen's pawn — you gain space and active pieces, but the d5-pawn may become a target. If Black plays Qb6, the centre gets traded off early and you enter a more open position where both sides race to develop. In every case, your plan stays the same: keep your pawn structure flexible, develop your queen's knight to d2 (not c3, since c3 is taken), and castle short. Patience wins this one.