Hedgehog

An understanding of Hedgehog structures is an essential component in any chessplayer's knowledge. These structures arise when the black c-pawn is exchanged early on for the white d-pawn (as in the Sicilian Defence). White then adopts a formation with pawns on c4 and e4 and Black curls up in a Hedgehog formation with pawns on a6, b6, d6 and e6.

These structures are important as they can arise from an extraordinary variety of openings including the Sicilian Defence, the English Opening and the...