Chessy
Playing White in the King's Pawn Game: Mengarini's Opening – Bc5
After 1.e4 e5 2.a3, things have already gotten a bit weird. Black can react in several ways, and the most popular choice is to snap off the pawn on f2 with the bishop. Instead, they usually develop — but that gives you a chance to learn something. The position after 2...Bc5 3.Nf3 is dead level according to the engine, scoring +0.06 (a tiny edge for White, but essentially equal). That means you are not worse despite the odd-looking early a3. Black has several reasonable moves, and a few tempting-looking ones that are actually mistakes. The drill below will help you navigate this offbeat line, punish Black's errors, and reach a comfortable middlegame. Let's break down what matters.
Play the King's Pawn Game: Mengarini's Opening: Bc5 against the engine
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This position has been played over 108,526 times in the Lichess database — not a huge number, but enough to spot real trends. White's overall results are 47.4% wins, 3.5% draws, and 49.1% losses, so Black scores slightly better in practice despite the engine calling it equal. Why? Because White's quiet start with 2.a3 gives Black easy targets if you don't play precisely. The key is knowing which Black moves are dangerous and which ones are gifts. The most popular reply, 3...d6 (34,200 games), sees White scoring just 46.7%, while the less common 3...Qf6 (8,030 games) actually gives White a 51.7% score — a clue that Black's flashy queen move isn't so sound.
The Engine's Choice: 3...d6
Stockfish recommends 3...d6 as Black's best response, planning to follow up with c3, Nf6, and d4 — a solid, classical setup. This move keeps the game in normal channels and avoids any immediate tactical tricks. When Black plays d6, your plan is straightforward: develop your pieces, control the centre, and don't panic about your early a3. The engine evaluation stays at +0.06, dead level. You're not worse, so just play natural chess. Against this reply, White scores 46.7% — slightly below par, but that reflects the difficulty of finding good plans in an unusual opening, not a fundamental problem with the position.
Three Black Mistakes You Can Punish
The biggest opportunity comes when Black plays one of three inaccurate moves. Here's what to look for: - 3...Nf6 (28,167 games, White scores 44.8%): This natural-looking knight development is an inaccuracy that loses about 0.7 pawns. The correct reply for White is to play aggressively — the engine says d6 was better for Black, so your position just improved. - 3...Qf6 (8,030 games, White scores 51.7%): Also an inaccuracy, losing about 0.8 pawns. Black brings the queen out early, which looks attacking but leaves it exposed. White scores well here — develop with tempo and you'll get the upper hand. - 3...Bxf2+ (6,238 games, White scores 47.5%): This is a full mistake, losing about 2.7 pawns. Black grabs material but wastes time and weakens their kingside. Take the 2.7 pawn advantage and don't let Black get compensation. All three of these are more popular than they should be — your opponents will often hang the game for you.
How to Handle the Most Common Replies
Let's go through the other popular moves Black might try. 3...Nc6 (16,543 games, White scores 47.8%) is a natural developing move — just play normal chess, develop, and castle. The engine still calls it equal. 3...a5 (2,599 games, White scores 48.1%) is a bit passive; Black weakens the b5 square and wastes a tempo. You can take over the centre with d4 soon. In every line, your general plan is the same: complete your development, fight for the centre (d4 is a key square), and castle kingside. The early a3 is a bit slow, but it also prevents ...Bb4 pins and can support b4 later if needed. Don't treat it as a wasted move — treat it as a useful pause while Black decides how to react.
Results across 108,526 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| d6 | 34,200 | 46.7% |
| Nf6 | 28,167 | 44.8% |
| Nc6 | 16,543 | 47.8% |
| Qf6 | 8,030 | 51.7% |
| Bxf2+ | 6,238 | 47.5% |
| a5 | 2,599 | 48.1% |
Frequently asked questions
Is 2.a3 really a good move in the King's Pawn Game?
It's unconventional but not bad. The engine rates the position after 3.Nf3 as dead equal (+0.06). The downside is that you've spent a tempo on a non-developing move, so you need to play accurately to avoid falling behind. The upside is that it prevents ...Bb4 pins and can support a later b4 advance. It's perfectly playable at club level.
What should I do if Black plays 3...Bxf2+?
This is a mistake that loses about 2.7 pawns for Black. Take the bishop with your king — don't worry about king safety, as Black has given up a piece for just two pawns and a check. Develop quickly, use your extra material, and don't let Black create counterplay. You're clearly better.
Why does 3...Qf6 give White such a good score (51.7%)?
Black's queen comes out early and becomes a target. You can chase it with tempo-gaining moves like d4, Nc3, or Be2, developing your pieces while Black has to move the queen again. Even though the engine says it's an inaccuracy (losing about 0.8 pawns), in practice White converts it to a win more often than usual.
Should I avoid this opening because of the 49.1% Black win rate?
Not at all. The 49.1% Black win rate reflects practical play at all levels, including games where White doesn't know how to follow up. The engine says the position is dead equal (+0.06). If you learn the key ideas — punish 3...Bxf2+, 3...Qf6, and 3...Nf6, and play solidly against 3...d6 — you can score very well with White.
How many games feature the King's Pawn Game: Mengarini's Opening: Bc5?
Over 108K Lichess games have reached the King's Pawn Game: Mengarini's Opening: Bc5 position. White wins 47.4%, Black wins 49.1%, with 3.5% draws — based on real rated games.