ECO A00 · Formation

Formation: Hippopotamus Attack

1. a3 e5 2. b3 d5 3. c3 Nf6 4. d3 Nc6 5. e3 Bd6 6. f3 O-O 7. g3

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Black to move. The arrow shows Stockfish’s best move.
Best move

7… Re8−1.82

Black is winning. Stockfish 18, depth 18.

Analyze this position

In the Formation: Hippopotamus Attack (A00), reached after 1. a3 e5 2. b3 d5 3. c3 Nf6 4. d3 Nc6 5. e3 Bd6 6. f3 O-O 7. g3, Stockfish 18 recommends 7… Re8 for Black. Black is winning (−1.82).

Top engine moves

  1. −1.827… Re8 8. Ne2 h5 9. c4 e4 10. fxe4 dxe4 11. d4 Bg4 12. Nbc3
  2. −1.757… e4 8. dxe4 dxe4 9. f4 Ne7 10. Ne2 Bg4 11. Qc2 Qd7 12. Bg2
  3. −1.707… Qe7 8. e4 Rd8 9. Qc2 a5 10. Nh3 b5 11. Nf2 Be6 12. Bg2

Frequently asked questions

What is the best move in the Formation: Hippopotamus Attack?
After 1. a3 e5 2. b3 d5 3. c3 Nf6 4. d3 Nc6 5. e3 Bd6 6. f3 O-O 7. g3, Stockfish 18 at depth 18 recommends 7… Re8 for Black, continuing 8. Ne2 h5 9. c4 e4 10. fxe4 dxe4 11. d4 Bg4 12. Nbc3. Black is winning (−1.82). The next best moves are 7… e4 (−1.75) and 7… Qe7 (−1.70).
Is the Formation: Hippopotamus Attack a good opening?
Stockfish rates the position at −1.82: Black is winning. That is a large edge for an opening position, so check the engine lines before playing it from the other side.
What is the ECO code of the Formation: Hippopotamus Attack?
A00. ECO codes classify chess openings from A00 to E99; A is the volume for flank openings.

Opening names from the Lichess opening book (CC0). Pieces by Colin M.L. Burnett (GPLv2+).