Speed: Bullet to Correspondence Rating:
Nf6 develops a piece and attacks the pawn on e4.
The Alekhine defense can lead to some wild positions, although the more popular ways of playing are more quiet. White can very quickly put a lot of pawns in the center with tempo. It's unclear how useful this big pawn center really is. It may just have left a lot of pawn weaknesses behind as it rushed forward.
This opening was first played at the top level in 1921 by World Champion Alexander Alekhine. It was considered incredibly unusual at the time because players were expected to try and establish a pawn in the center on the first move. To give your opponent numerous pawns in the center while wasting time moving the same knight around many times seemed crazy.
However, its now seen as a perfectly normal, if not incredibly popular opening and has been played by many strong GMs. Magnus Carlsen, Bobby Fischer and Hikaru Nakamura have all played the Alekhine in serious games.