Chessy
Modern Defense: Mongredien Defense, with Nf3: Bc4 — Playing as Black
You've played 1...g6, 2...Bg7, 3...b6, and now 4...c6. You're steering the game into the Mongredien Defense, a sideline of the Modern Defense that aims to challenge White's centre from the flanks. Let's be honest: the engine gives White a clear edge here, so you are worse from the start. But that doesn't mean the position is hopeless — it just means you need a plan and a healthy respect for White's space advantage. Let's look at what the statistics and engine analysis reveal about this position, and how you can put up the toughest resistance.
Play the Modern Defense: Mongredien Defense, with Nf3: Bc4 against the engine
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Create a free account →The Position at a Glance
After 1.e4 g6 2.d4 Bg7 3.Nf3 b6 4.Bc4 c6, White enjoys a comfortable development lead. Stockfish rates this +1.15, which is a clear advantage for White. Across 1,735 games in the Lichess database, White wins 55.0%, draws are rare at 3.6%, and Black wins 41.4%. So while the odds favour your opponent, Black still scores respectably when they navigate the early moves well. The key is knowing which of White's moves to welcome — and which to punish.
White's Best Move — and Why
The engine's top choice is Nc3, a natural developing move that reinforces White's control of the centre. The suggested follow-up is Nc3 d6 Bb3 Nf6, bringing Black's pieces out while White retreats the bishop to a safe diagonal. From here Black has a solid, if slightly passive, position. If you face Nc3, you should be ready for a patient game where you complete development and look to challenge White's centre with moves like ...e6 or ...d5 when the time is right.
Common White Mistakes to Exploit
The good news: many of White's most popular moves are actually inaccuracies or outright mistakes. Here are the three to watch for, all of which improve your chances significantly compared to the engine's best line: O-O — This is the most-played move (474 games) but it is an inaccuracy, losing about 0.6 pawns. White castles without any preparation, allowing you to seize the initiative. Ng5 — Played 277 times, this is a mistake (losing ~1.1 pawns). The knight hop looks aggressive but leaves White's kingside vulnerable. d5 — This push, seen in 74 games, is also a mistake (losing ~1.0 pawns). White opens the centre prematurely without proper development. If your opponent plays any of these, you have real winning chances.
Your Plan After O-O (White's Most Common Move)
Since O-O is both the most popular White response and an inaccuracy, it deserves special attention. After White castles, the engine says you are much better off than if they had played the correct Nc3. Your development plan remains similar — get your knight to f6, play ...d6, and castle yourself — but now you have a tangible advantage to work with. The bishop on c4 can become a target, and White's kingside castling may prove premature if you can open lines later. Stay alert for tactical opportunities, because in 474 games White scored only 56.3% here — meaning Black wins nearly as often as they should given the initial evaluation.
Surviving the Opening as the Underdog
Playing the Mongredien Defense means accepting a slight disadvantage from move 5 in exchange for a sharp, less-booked position. Your job is to keep the game complicated. Avoid passive setups that let White steamroll you — the statistics show that Black scores 41.4% overall, which is decent for a position that's +1.15 in White's favour. Focus on completing development, keeping your pawn structure flexible, and looking for the moment when White's overambitious play (like Ng5 or early d5) gives you counterplay. If White plays the engine move Nc3, be patient and aim to equalise gradually in the middlegame.
Results across 1,735 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| O-O | 474 | 56.3% |
| Nc3 | 296 | 58.8% |
| Ng5 | 277 | 55.2% |
| c3 | 153 | 54.2% |
| e5 | 112 | 55.4% |
| d5 | 74 | 45.9% |
Frequently asked questions
Is the Modern Defense: Mongredien Defense playable for Black?
It's playable but challenging. The engine gives White a clear edge at +1.15, and Black wins 41.4% of games from this position. You are objectively worse, but the position is less theoretical than mainstream Modern lines, and many White players mishandle it — O-O, Ng5, and d5 are all mistakes that improve your chances.
What is White's best move against the Mongredien Defense with Bc4?
The engine's top choice is Nc3, developing the knight and supporting the centre. The best continuation from there is Nc3 d6 Bb3 Nf6, where White is slightly better but Black has a solid, defensible setup.
How should Black respond if White plays Ng5?
Ng5 is a mistake that loses about 1.1 pawns compared to the best move Nc3. You should be happy to see this aggressive knight move. Develop naturally, keep your cool, and the statistics suggest your position will improve significantly.
Why is O-O considered an inaccuracy for White here?
O-O loses about 0.6 pawns compared to the engine's best move Nc3. Despite being the most common move (474 games), castling early gives Black time to complete development and seize the initiative. White scores 56.3% after O-O, which sounds good but is actually below what the position should yield.