Chessy
The Rat Defense: Petruccioli Attack – A Shock Weapon for White
If you like to drag opponents out of their comfort zone in move two, the Rat Defense: Petruccioli Attack (1.e4 d6 2.h4) is your kind of opening. It is an ultra-aggressive pawn thrust that says you are ready to attack on the kingside before standard development is even finished. Statistically, Black scores 49.7% in this position across over 21,910 games — but White still scores a respectable 45.1%. Stockfish calls it dead level at -0.08, meaning you give up nothing by playing it. The drill below lets you practice meeting Black's most common answers and punishing their inaccuracies right away.
Play the Rat Defense: Petruccioli Attack against the engine
Free, no signup — you play white, the engine adapts to your level.
Play through the position against the adaptive engine below — practice meeting Black's best replies and learn to punish their inaccuracies in real time.
Create a free account →What You Are Fighting For
After 1.e4 d6 2.h4 the board looks unusual, but the idea is straightforward: you want to push h5, chase away a Black knight that lands on f6, and open lines on the kingside. Black's best response is 2...c5, the engine's top choice, leading to a solid fight after 3.Nc3 Nc6 4.Nge2. Notice that you develop naturally — the h-pawn does not stop you from getting your pieces out. If Black does not play accurately, you can gain real advantages. Your plan is simple: develop, keep the centre stable, and use the half-open h-file as a weapon later.
The Engine's Best Line
If Black plays perfectly, the engine recommends 2...c5 (controlling d4 and challenging your centre). Your job then is 3.Nc3 Nc6 4.Nge2, preparing to meet ...d5 or ...e5 with solid central play. You are not wild here — you are playing principled chess with an extra attacking resource on the h-file. If Black deviates from this line, you often end up with a more pleasant game than the statistics suggest.
What the Statistics Reveal
Across 21,910 games from this exact position, White wins 45.1% of the time — a healthy number for an offbeat second move. The most popular reply by far is 2...Nf6 (8,375 games), where White scores 44.3%. Black immediately attacks your e-pawn, but you can play 3.h5 or 3.Nc3 knowing that your h-pawn is a long-term asset. Other common moves include 2...e5 (3,453 games, White scores 46.6%) and 2...g6 (2,283 games, White scores 45.5%). The numbers are close enough that you should never fear this opening — you are fighting for a win just as much as Black is.
Punishing Black's Inaccuracies
Three of Black's natural-looking replies are actual inaccuracies you can exploit. 2...g6 is rated as an inaccuracy — the engine says 2...Nf6 was better, with a centipawn loss of 85. Similarly, 2...e6 (67 centipawns lost) and 2...Nc6 (65 centipawns lost) are both inferior to 2...Nf6. Why? Because moves like ...g6 and ...e6 do not challenge your centre or develop quickly enough, while ...Nc6 allows you to push d4 with tempo. When Black plays one of these, you can simply continue developing with confidence, knowing the computer thinks you are already slightly better than the
Results across 21,910 Lichess games
| Most-played continuation | Games | White wins |
|---|---|---|
| Nf6 | 8,375 | 44.3% |
| e5 | 3,453 | 46.6% |
| g6 | 2,283 | 45.5% |
| e6 | 1,546 | 45.8% |
| c6 | 1,134 | 43.7% |
| Nc6 | 805 | 45.5% |
Frequently asked questions
Is the Rat Defense: Petruccioli Attack a good opening for beginners?
It is a reasonable choice if you enjoy unusual positions and want to avoid long theoretical lines. The engine evaluates it as dead level (-0.08), so you are not making a concession. Just remember to follow up with normal development and not overextend with your h-pawn.
What is Black's best response to 2.h4?
The engine's top move is 2...c5, aiming to seize space in the centre. After 3.Nc3 Nc6 4.Nge2, the game remains balanced. The most popular human reply is 2...Nf6, putting immediate pressure on your e4-pawn.
Should I always push h5 after 2.h4?
Not automatically. If Black plays 2...Nf6, pushing h5 can be a good way to gain space and threaten h6. But if Black ignores your h-pawn and develops solidly, focus on central development first — the h-file will still be there later.
Why are 2...g6 and 2...e6 considered inaccuracies?
They are rated as inaccuracies compared to the best move 2...Nf6, costing 67–85 centipawns. Playing ...g6 or ...e6 does not challenge your centre or develop a piece with tempo, allowing you to seize space or build a strong pawn centre before Black can react.
How many games feature the Rat Defense: Petruccioli Attack?
Over 21K Lichess games have reached the Rat Defense: Petruccioli Attack position. White wins 45.1%, Black wins 49.7%, with 5.2% draws — based on real rated games.