The Modern Defense: Mongredien Defense with Nf3: c4 — Playing as Black

This position is all about the centre — specifically, the dark squares around your king. Your fianchettoed bishop on g7 is a powerhouse on the long diagonal, but it needs support. Black's most natural plan is to play d6, Nd7, and eventually challenge White's centre with e5 or c5. The pawn on b6 and the bishop on b7 aim at White's queenside, but that attack is a long-term project. In the short term, your main job is to complete development without letting White's central space advantage crush you. White's best move, Nc3, followed by Bd3, builds a classical pawn centre on d4 and e4 that can feel suffocating if you don't react in time.

Stockfish's best continuation is Nc3, and then d6 Bd3 Nd7. That sequence says a lot: White develops naturally and dares you to find a plan. Your response of d6 immediately stakes a claim in the centre and prepares to develop your knight to d7. From there, Nd7 eyes the f6-square (blocking the bishop's diagonal temporarily, but also preparing e5 or f5 breaks). The resulting setup is solid: Black has no immediate weaknesses, and White still needs to decide whether to castle kingside, go for an early e5 push, or reposition pieces. Your task is simple: stay flexible, avoid passive moves, and wait for the moment to open the position for your bishops.

Across 214,418 games from this position, the results are surprisingly close for a position the engine favours White at +0.86. White wins 50.5% of games, Black wins 45.8%, and draws happen just 3.7% of the time. That high Black win rate means the position is far from hopeless — it's just demanding. If you handle the opening well, you can absolutely outplay your opponent in the middlegame. The low draw rate (3.7%) also tells you this is a fighting opening: games tend to be decisive, so look for active counterplay rather than trying to simplify into a draw.

Not all White replies are equal, and the statistics back this up. The engine identifies several suboptimal moves White can make — and you should be ready to pounce. The most dangerous for you? Actually, some moves are worse for White, so know what's coming. Here's what the engine says: - e5 is an inaccuracy, losing about 0.7 pawns. White should have played Bd3 instead. If White pushes e5, you gain ground and can challenge the centre more easily. - Be3 is a full mistake, losing about 1.5 pawns. Be2 is also a mistake, also losing about 1.5 pawns. Both should have been Bd3. If your opponent plays either bishop move, the position swings in your favour significantly — look for active play immediately. As Black, these are the moments to take over. The statistics show that when White plays the inaccurate e5, their score drops to 46.2%, and after Be3 it falls to 46.1% — real opportunities for you.

White's most popular move by far is Nc3 (150,796 games, 51.0% score), followed by Bd3 (27,397 games, 50.9%). Both score similarly well for White. The engine says Bd3 is best, but in practice Nc3 is just as effective. Against Nc3, your plan is d6 then Nd7 — simple and sound. Against Bd3, you can play the same ideas since the position is similar. The tricky one is d5 (22,753 games), where White scores only 48.9% — below 50%! If White pushes d5, they're giving you a target. You can recapture with the e-pawn or develop with Nf6, opening lines for your bishops. The e5 push (6,317 games, 46.2% for White) is the inaccuracy mentioned earlier — if you see e5, you know you've gained ground. Be ready to grab space and activate your pieces.