Author dives into the QID Petrosian variation (4 a3) which was a Kasparov favorite.   Divided by 4th and 5th moves, the author presents full games (un-numbered) well-analyzed with explanation, original lines, and fragments.   Main sub-variations conclude with test positions (109 total) with solutions at end of book.   Figurine algebraic notation.   Index of games.  104 pages