Book excerpt: The Pirc Defence is a sharp hypermodern opening in which black tempts white establishing a pawn centre with the idea of rapidly undermining it. Its unbalanced nature ensures exciting play and invariably this leads to a decisive result. Leading modern exponents include World Championship candidates finalist Jan Timman, American Grandmaster Yasser Seirawan and Britain's Jon Speelman. Here John Nunn, himself, an expert on the Pirc Defence, presents his selection of the most theoretically important recent games.