Fascinating book. Good instructions for the beginning-to-intermediate player. It is also fascinating to peek inside the minds of 7 of the world's best grandmasters (of the 1970s) and learn from their different styles. Each grandmaster contributes a chapter to the book. This is not a collaboration so there is no continuity among the chapters. Each grandmaster discusses in - I think - about 30 pages or so an aspect about opening a chess game. While this is very interesting, you may not get the depth of instruction you desire.