<p>The Sicilian Defense is the most popular and most complex of opening systems in chess. It has been the favorite of top players throughout modern times. There are a number of systems and variations to choose from such as the Scheveningen, Dragon, Najdorf, Boleslavsky, Kan, etc. There are also a number of sharp, complex, theoretical systems and that is why it is aptly named &ldquo;The Sicilian Jungle.&rdquo; IM Dr. Danny Kopec&rsquo;s addresses the problem of trying to simplify the complexities of the Sicilian Defense from the perspective of STRUCTURE &ndash; that is, sound structures for Black, particularly for the endgame. Dr. Kopec uses a unique method which he calls &ldquo;Mastery Lessons&rdquo; to guide the learner towards pawn structures and piece configurations which have been demonstrated to lead to success in certain Sicilian variations. This approach, developing &ldquo;heuristic packets&rdquo;, helped to achieve master level play in his work with computer chess programs.</p>