Chessy
King's Pawn Game: Mengarini's Opening – d5
After 1.e4 e5, the unassuming 2.a3 looks modest, but don't be fooled. If Black responds with 2...d5, you capture 3.exd5 and reach a position where Stockfish gives White a +0.38 edge — a small but real advantage. From the resulting position, Black has several replies, and how you handle them determines whether you keep that edge or hand it back. The drill below will sharpen your instincts for this line, so you can punish inaccurate play and steer the game toward comfortable positions.
Play the King's Pawn Game: Mengarini's Opening: d5 against the engine
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Jump into the interactive drill and practise these positions against an adaptive engine. See if you can convert White's +0.38 edge into a full point.
Create a free account →What 2.a3 Brings to the Table
At first glance, a3 looks like a wasted move. But in the Mengarini's Opening, the point is to maintain flexibility. By playing 2.a3, you prevent Black from pinning your knight with ...Bb4 after a later Nc3, and you keep options open for a d3 or c3 setup. When Black challenges the centre with 2...d5, you take with 3.exd5 and emerge with a +0.38 advantage — a small edge, but a clear one for White. The pawn on d5 is a temporary central presence, and your job is to develop quickly while Black figures out how to recover the pawn.
The Most Popular Reply: 3...Qxd5
By far the most common response (43,946 games) is 3...Qxd5, giving Black the pawn right back. White scores a solid 53.6% from this position. The queen comes out early, which means Black will have to move it again once you develop with tempo. Your natural plan is to play Nc3, attacking the queen and gaining time. After the queen retreats, continue developing with Nf3, Bc4, and O-O, aiming for a lead in development and a slight pressure advantage. This is a straightforward, principled way to handle Black's most popular try.
When Black Plays 3...Nf6 (The Engine's Choice)
The computer's top recommendation for Black is 3...Nf6, which occurs in 4,769 games. Here White scores only 45.4%, so you need to be precise. The engine's suggested continuation is 4.Bb5+ Nbd7 5.Nc3. The check on b5 is key — it forces Black to block with ...Nbd7, which can lead to a slightly passive setup. After Nc3, you are ahead in development and can follow up with d4 or Nf3 depending on how Black recaptures. Even though White's winning percentage dips here, the engine evaluation (+0.38) shows you are still slightly better if you follow the best plan.
Avoid the Mistake: e4 Is a Dud
A tempting idea for Black is 3...e4 — pushing the e-pawn forward to cramp White's position. But the FACTS show this is a mistake, losing roughly 1.3 pawns in evaluation. The correct move for Black in that position would have been 3...Nf6. If your opponent plays e4, you should be happy. Develop naturally with Nc3 or d3, challenge the advanced pawn, and enjoy your material advantage. In 507 games after 3...e4, White scores 50.9%, so while it's winning in the engine room, you still need to convert carefully.
Results across 53,360 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| Qxd5 | 43,946 | 53.6% |
| Nf6 | 4,769 | 45.4% |
| c6 | 2,383 | 45.2% |
| Bc5 | 557 | 51.3% |
| e4 | 507 | 50.9% |
| Bd6 | 373 | 50.9% |
Frequently asked questions
What is the King's Pawn Game: Mengarini's Opening?
It's an offbeat opening beginning with 1.e4 e5 2.a3. White spends a tempo on a useful waiting move, avoiding mainline theory while preparing to develop without worrying about ...Bb4 pins. After 2...d5 3.exd5, the position is slightly better for White (+0.38).
Is 2.a3 a good opening for beginners?
Yes — it sidesteps heavy theory while keeping a small advantage. The resulting positions are straightforward: you develop quickly, challenge Black's queen if it comes out early, and rely on basic principles. With a 52.5% White win rate across over 53,000 games, it's a practical choice.
How should White respond to 3...Qxd5?
Develop with tempo by playing Nc3, attacking the queen. Black will have to move it again, and you gain time to bring out your pieces. Follow up with Nf3, Bc4, and short castling. White scores 53.6% in this line, which is the most common continuation.
What if Black plays ...Bc5 instead of recapturing on d5?
After 3...Bc5 (557 games, White scores 51.3%), you can continue developing normally with Nc3 or Nf3, and consider d4 to challenge the bishop. Black has left the pawn on d5 hanging, and you don't need to rush to defend it. Just bring your pieces out and maintain your small edge.