An excellent monograph by a German theorist with in-depth coverage of the hedgehog formation (in German Igel) arising from the Sicilian Paulsen/Kan/Scheveningen- complex.
The hedgehog formation (typically black pawns on a6-b6-d6-e6 against white centre pawn on c4 and e4 with Black's c-pawn exchanged against White's d-pawn) is characteristic of several lines in the English Opening and, especially, the Sicilian Defence.
It is famous for its esilience and flexibility, qualities that can drive an author crazy. In this German-language monograph Frank Zeller manages to explain this highly complicated matter in admirable fashion.
The theory of the Paulsen/Kan/Scheveningen-complex is dissected along the lines of the development of White's king's bishop: the classical Be2, the fianchetto (g3 & Bg2), a scheme involving Bd3 and f2-f4, etc.
A five-page index helps the reader navigate through the thicket of lines and transpositions. Conclusion: a useful guide.
