Alekhine's Defence

1...Nf6 makes an immediate attack on the e4-pawn. The main idea of the Alekhine is to provoke White to advance and push pawns, which Black can pick at later. This leads to an asymmetric and unbalanced game and aggressive tactical opportunities.

2. e5 is the main move. White takes more space and kicks Black's knight, usually to d5. White is able to keep taking space in the centre: they must weigh taking more space against developing their minor pieces. Meanwhile, Black hopes that White's pawn centre will be overextended and so possible to exploit later in the game.

2. Nc3, defending the pawn, is an alternative. If 2...e5 this transposes into the Vienna game, otherwise 2...d5, the Scandinavian variation, has its own original and transpositional possibilities.

2. Bc4?!, the Krejcik variation, allows Black to take on e4, 2...Nxe4, with the idea to win the material back with 3. Bxf7+ Kxf7 4. Qh5+ Kg8 5. Qd5+ e6 6. Qxe4 d5 ⩱. This is flashy sequence is not thought to be great for White however: Black's king is safe on g8 and White has given up the space advantage and the bishop pair.

The opening is named after Alexander Alekhine, who played it in Budapest in 1921.^[1][2] The tournament, where Alekhine triumphed, was his first international chess tournament since 1914 and put an end to the rumour that he had died during the Russian Revolution. The British Chess Magazine reported, "[Alekhine] proved that, in spite of his Bolshevist experiences, he is still the great player that he was before the war."^[3]

Some earlier appearances of the defence are known: it was among the lines analysed by Allgaier in his 1819 work, and anecdotally Alexander McDonnell (1798―1835) would sometimes employ 1. e4 Nf6 2. e5 Ng8?!, later termed the Brooklyn variation, to induce White to overextend their centre.^[4] A game in the four pawns attack, 1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. c4 Nb6 5. f4, was recorded between Lenin (the Russian revolutionary) and Maxim Gorky in 1908.^[5]

It is not unsound, though conceding the space advantage can be dangerous for Black. While it is not played very often at master level, it appears occasionally as a surprise weapon.

1. e4 Nf6

Wikipedia has related information at Alekhine's Defence.