This book is part of a series examining the cutting edge of chess opening theory. The idea is to identify the most important theoretical battlegrounds of the moment and then analyze as deeply as possible in search of improvements. Thus the reader will be ahead of the current state-of-the-art, rather than lagging behind trying to memorize old games. This volume deals with the Sicilian Najdorf, a favorite opening of ambitious players at every level. It covers variations after White chooses the popular 6.Be3, heading for the English Attack, and includes the Topalov Variation, the Perenyi Attack, as well as lines with 6.e5.