Alekhine Defense: O'Sullivan Gambit

Before the first move

The Alekhine Defense is a provocative opening where Black lures White's center pawns forward, hoping they become overextended and weak. In the O'Sullivan Gambit, Black takes this a step further by offering a wing pawn early to disrupt White's spatial advantage and create unique tactical complications.

1. e4White

White plays e4, the most common and ambitious start. By seizing the center immediately, White prepares for rapid development. As Black, you must decide how to respond: will you meet it symmetrically with e5, or try an asymmetrical approach like the Sicilian Defense or the French Defense?

1... Nf6Black · your move

Develop your knight to f6. This is the hallmark of the Alekhine Defense. You are immediately attacking the e4-pawn and inviting White to push it forward. It is a hypermodern approach that focuses on attacking the center from a distance rather than occupying it.

Other paths here: f6 (Barnes Defense) · g5 (Borg Defense) · h6 (Carr Defense) · f5 (Duras Gambit)

2. e5White

White plays e5, the main line, gaining space and harassing your knight. While White could try the Maróczy Variation with d3 or the Scandinavian Variation with Nc3, the pawn push is the most testing. You must now find a safe and active home for your knight.

Other paths here: Nf3 (John Tracy Gambit) · Bc4 (Alekhine Defense: Krejcik Variation) · d3 (Alekhine Defense: Maróczy Variation) · Nc3 (Alekhine: Scandinavian Variation)

2... Nd5Black · your move

Move your knight to d5. This centralizes your piece in the heart of the board. From d5, the knight is very influential, even though it may be attacked again. It is the standard follow-up to White's pawn push, keeping the pressure on the d-pawn.

Other paths here: Ng8 (Alekhine Defense: Brooklyn Variation) · Ne4 (Alekhine Defense: Mokele Mbembe)

3. d4White

White plays d4, establishing a formidable pawn duo in the center. This is the most common approach, though White sometimes tries the aggressive Four Pawns Attack or the Two Pawns Attack with c4. You are now facing a wall of pawns and must find a way to break through.

Other paths here: Na3 (Alekhine Defense: Buckley Attack) · Nc3 (Alekhine Defense: Sämisch Attack) · c4 (Alekhine Defense: Two Pawns Attack) · b3 (Alekhine Defense: Welling Variation)

3... b5Black · your move

Push your pawn to b5. This is the O'Sullivan Gambit. You are offering a pawn to distract White from the center and create immediate tension on the queenside. It is a sharp alternative to the standard d6 or the Wall Variation with c5.

Other paths here: d6 (Alekhine Defense) · c5 (Wall Variation, Alekhine)

Where you stand

The position is highly unbalanced. White has a massive center and can accept the gambit, while Black relies on rapid piece play and pressure against the e5-pawn. White should focus on safe development and king safety, while Black will likely use the c-pawn and d-pawn to undermine the white center.

• f1-b5 White captures the gambit pawn on b5
• c8-b7 Develop the bishop to the long diagonal
• d7-d6 Challenge the e5-pawn to break the center
• g1-f3 Develop the knight and prepare to castle