The Crab Opening arises after 1.a4 e5 2.h4. ECO code: A00.

Overview

The name "Crab Opening" derives from the sideways pawn moves on both flanks—a1-pawn to a4 and h-pawn to h4—evoking the lateral movement of a crab. White makes two flank pawn moves while Black occupies the centre with ...e5.

Strategic Themes & Plans

White has wasted two tempi on rook-pawn advances that contribute nothing to development or central control. The resulting position gives Black a significant lead in development and central space. Black should continue with straightforward central development: ...d5, ...Nf6, ...Bc5, and rapid castling. The Crab Opening is considered among the most dubious of all opening sequences and has no presence in competitive chess. Its sole attraction is novelty value.