Ninth World Champion Tigran Petrosian, 1929-1984, was known for his positional sense and his ability to play complex strategic positions. This book provides a detailed analysis of 36 games with Petrosian's positional exchange sacrifice. Indexes of players and openings. Pictures 2 and 3 show the list of games. Author is strong GM and trainer, 10x Greek Champion. He wrote ca 15 books, among them a pentalogy Kotronias on the King's Indian 1-5, The Safest Scandinavian (3..Dd6), The Sicilian Sveshnikov and others.