Professor Dumbledore's Great Game (abbreviated as "BI") is a theory created by the authors anna_y and catherine and posted on the Internet (in particular on LiveJournal, Livejornal.com) in 2005, 2006 and 2007. The most important (and at that time sensational) conclusion of this theory was the assertion that Professor Dumbledore was playing some kind of complex game, calculated for many years in advance, the goal of which was to defeat Voldemort. And the main trump card of this game is Harry Potter, for the correct education of whom Dumbledore goes to all sorts of tricks. The theory is replete with interesting analyzes of both the psychological portraits of individual characters and many scenes, written in lively language with a considerable amount of humor. Long before the appearance of the seventh book, Anna and Katerina stated that Severus Snape was sincerely devoted to Albus Dumbledore. Considering the adult works of JK Rowling, the BI theory is very likely.