Chessy
The Modern Defense: Mongredien Defense with Nf3 Nc3 — Playing as Black
The Mongredien Defense is a bold, offbeat way to meet White's classical centre with 1.e4 g6 2.d4 Bg7 3.Nf3 b6. After the natural 4.Nc3 Bb7, you've fianchettoed both bishops and are ready to pressure White's central pawns — but you've also given White a very comfortable score. The statistics are honest: from this exact position, White wins 51.4% of games, Black wins 44.6%, and only 4.0% end drawn. The engine rates this position at +1.27, a clear advantage for White, meaning you are objectively worse here and need to play accurately to avoid being overrun. Your task is to steer this tricky, double-edged setup toward something you understand better than your opponent.
Play the Modern Defense: Mongredien Defense, with Nf3: Nc3 against the engine
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Set up the position on the interactive board below and play through the Mongredien Defense as Black against a training engine. The more you practise, the more 5
Create a free account →What You're Fighting For — The Double Fianchetto
By playing 3...b6 and 4...Bb7 you've committed to a Double Fianchetto setup (both bishops on b7 and g7). Your main idea is to let White build a big centre with pawns on d4 and e4, then attack it from the flanks. The bishop on b7 eyes the e4-pawn, while the bishop on g7 works along the long diagonal. In return, White has easy development and central space. Because your position is cramped, you must look for timely pawn breaks (like ...c5 or ...d6 followed by ...e5) to challenge White's centre before their pieces overwhelm you. Patience is key — rushing without preparation will let White's +1.27 advantage turn into a winning attack.
The Engine's Harsh Answer — 5.h4
Stockfish's top recommendation for White is h4, followed by h4 h6 Bf4 d6. White wastes no time attacking your kingside, threatening to open lines against your fianchettoed king. The move h4 is a direct, aggressive answer to your set-up. If you face 5.h4, the natural reply is 5...h6 to stop h5-h6, though the statistics show very few games reach this exact line. Your plan should be to complete development with ...d6, ...Nd7 or ...Nf6, and eventually look for ...c5 or ...e5 to break the centre. Remember: White's advantage comes from space and attacking chances — if you can trade off some pawns and reach a simplified middlegame, the engine's +1.27 will be much harder for White to convert.
The Most Common Continuations — What White Actually Plays
In practice, White's human players rarely find the engine's h4. Here are the most popular replies and what they mean for you: Be3 (538,618 games, White scores 51.5%) — White simply develops and prepares to castle. You should aim for ...d6 and ...Nd7, waiting for White to commit. Bd3 (528,483 games, White scores 51.4%) — White eyes the h7-square. Be careful not to weaken your kingside pawns unnecessarily. Bc4 (469,280 games, White scores 53.0%) — The sharpest of the popular choices, targeting f7. You must reply with ...d6 or ...e6 to control d5. Notice that e5 (259,362 games, White scores only 49.4%) is actually White's worst-scoring option — if White pushes the e-pawn too early, you can equalise more easily by trading on e5 and opening the long diagonal for your bishops.
What the Statistics Reveal — Practical Survival Tips
Your chances as Black are better than the engine evaluation suggests. Though Stockfish gives +1.27, Black still wins 44.6% of games — nearly half. The key is avoiding the most common Black mistakes. In positions like this, typical Black errors include: playing ...c5 too early without preparation (letting White's knights dominate), neglecting to castle quickly, or falling for tactics on the a1-h8 diagonal. Here are practical tips: develop your knights to f6 and d7, castle short (kingside), and always check if White can play e5 or d5 to gain space. If White plays Bc4, treat f7 as a target for at least the next two moves. Against Be3 or Bd3, you have time to play ...d6, ...Nd7, and ...e5 to challenge the centre. The Mongredien Defense rewards creative, alert play — but one inattentive move can make your position very hard to defend.
Results across 2,351,256 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| Be3 | 538,618 | 51.5% |
| Bd3 | 528,483 | 51.4% |
| Bc4 | 469,280 | 53.0% |
| e5 | 259,362 | 49.4% |
| d5 | 144,904 | 50.0% |
| Bf4 | 135,168 | 51.6% |
Frequently asked questions
Is the Mongredien Defense a good opening for beginners?
It is playable but challenging for beginners. The engine gives White a +1.27 advantage, so you start objectively worse. However, the practical statistics show Black still wins 44.6% of games, meaning many White players don't know how to punish it. If you enjoy double-fianchetto setups and are comfortable defending slightly worse positions, it can be fun to learn.
How should Black respond to 5.h4 in the Mongredien Defense?
The engine's top reply is 5...h6 to stop h5-h6, followed by White playing Bf4 and d6. After h6, you should aim to complete development with ...d6, ...Nd7 or ...Nf6, and prepare a central break like ...c5 or ...e5. Just be careful not to let White's pawn storm open lines against your king.
What is White's worst-scoring move in this position?
According to the Lichess database of 2,351,256 games, the move e5 gives White its lowest scoring percentage at 49.4%. If your opponent pushes the e-pawn early, that is relatively good news for you — you can trade on e5 and free your bishops on the long diagonals.
Why does Black fianchetto both bishops in the Mongredien Defense?
The double fianchetto aims to pressure White's central pawns from both flanks. The bishop on b7 attacks e4, while the bishop on g7 attacks d4. This setup can be very solid if you manage to break open the centre at the right moment. The downside is that White gets a large space advantage and attacking chances, which matches the +1.27 evaluation.