Rat Defense: Antal Defense
The Antal Defense of the Rat is 1.e4 d6 2.d4 Nd7, developing the knight to support ...e5 instead of placing it on f6. White takes space with f4 or Nc3, while Black aims for ...e5 and ...Ngf6.
- Moves
- 1.e4 d6 2.d4 Nd7
- ECO
- B00
- Engine
- +0.68 · a slight edge for White (Stockfish 17.1, depth 20)
- Played
- 2,203 games in our lichess sample
- White scores
- 51.0%
Key ideas for both sides
White
- 3.f4 adds a third pawn to the center and stops ...e5 from coming easily.
- After ...e5 and ...exd4, recapture with the queen and play Nc3 and Nf3 for a lead in development.
- 3.Nf3 with Bc4 aims at f7, a weak point while the d7 knight blocks Black's bishop.
- Keep the center broad and develop quickly; Black's setup is a bit slow.
Black
- Play ...e5 next, supported by the d7 knight and the d6 pawn.
- Follow with ...Ngf6 so the king's knight still reaches f6 and controls e4.
- After the trade on d4, play ...c6 to keep the queen out of b5 and prepare ...d5.
- Watch f7 when White's bishop is on c4; ...Be7 and castling help.
Plans and pawn structure
Black's setup aims for ...e5 with the knight on d7 supporting it. White gets a large center with e4 and d4, and often f4 too. If Black takes on d4, White recaptures with the queen and develops with Nc3, Nf3 and Bf4, getting a space advantage. Black's plan is ...Ngf6, ...Be7, ...c6 and castling, then ...d5 to fight the center. The d7 knight can block the c8 bishop, so Black must free it later.
What the engine plays from here
Stockfish 17.1 at depth 20 rates the position +0.68: a slight edge for White. Its three top choices for White:
- +0.68 3.f4 e5 4.Nc3 Ngf6 5.Nf3 exd4
- +0.66 3.Nc3 e5 4.f4 Ngf6 5.Nf3 exd4
- +0.62 3.Nf3 e5 4.Bc4 exd4 5.Qxd4 Ngf6
Pawns, from White's side.
How it scores on lichess
2,203 rated lichess games reached this position; White scored 51.0%.
Light: White wins. Grey: draws. Dark: Black wins. About the sample.
How to play against it
As White, take space with 3.f4 or 3.Nc3 and develop fast. Do not rush to trade the center; Black's pieces are cramped. If Black plays ...exd4, take back with the queen and use the time for Nc3 and Bf4, keeping a lead in development.
Questions
What are the moves of the Rat Defense: Antal Defense?
The Rat Defense: Antal Defense starts 1.e4 d6 2.d4 Nd7. Its ECO code is B00.
Is the Rat Defense: Antal Defense good for Black?
Stockfish 17.1 rates the position +0.68 at depth 20, which is a slight edge for White. In 2,203 lichess games from our sample, White scored 51.0%. A solid but passive choice for Black, while White gets easy space and simple development.
What is the main idea of the Rat Defense: Antal Defense?
Black puts the knight on d7 to support ...e5. White grabs space with f4 or Nc3 and develops quickly, aiming to use the lead in the center.
What should White play next?
The engine's first choice is f4, with Nc3 and Nf3 close behind. 3.f4 adds a third pawn to the center and makes ...e5 harder to achieve.
Related lines
Updated October 2026. Sources and method.