ECO B03 · Alekhine Defense

Alekhine Defense: O'Sullivan Gambit

1. e4 Nf6 2. e5 Nd5 3. d4 b5

abcdefgh87654321
White to move. The arrow shows Stockfish’s best move.
Best move

4. Bxb5+1.40

White is clearly better. Stockfish 18, depth 18.

Analyze this position

In the Alekhine Defense: O'Sullivan Gambit (B03), reached after 1. e4 Nf6 2. e5 Nd5 3. d4 b5, Stockfish 18 recommends 4. Bxb5 for White. White is clearly better (+1.40).

Top engine moves

  1. +1.404. Bxb5 c5 5. c4 cxd4 6. Qxd4 Qb6 7. Qxb6 Nxb6 8. Be3 Bb7
  2. +1.024. Nh3 a6 5. Nc3 Bb7 6. Nxd5 Bxd5 7. Nf4 Bb7 8. Be2 Nc6
  3. +0.994. Nf3 a6 5. a4 b4 6. c4 bxc3 7. Nxc3 Nb4 8. Ng5 Bb7

Frequently asked questions

What is the best move in the Alekhine Defense: O'Sullivan Gambit?
After 1. e4 Nf6 2. e5 Nd5 3. d4 b5, Stockfish 18 at depth 18 recommends 4. Bxb5 for White, continuing c5 5. c4 cxd4 6. Qxd4 Qb6 7. Qxb6 Nxb6 8. Be3 Bb7. White is clearly better (+1.40). The next best moves are 4. Nh3 (+1.02) and 4. Nf3 (+0.99).
Is the Alekhine Defense: O'Sullivan Gambit a good opening?
Stockfish rates the position at +1.40: white is clearly better. Evaluations this early in the game are small, so practical results depend far more on knowing the plans and typical structures than on the engine's number.
What is the ECO code of the Alekhine Defense: O'Sullivan Gambit?
B03. ECO codes classify chess openings from A00 to E99; B is the volume for semi-open games (other than the French).

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