The monograph of the famous theorist, international grandmaster Bagirov is devoted to the study of one of the newest chess openings - Alekhin’s defense. The author, an internationally recognized specialist in this field, summarized and systematized his many years of research on the defense of Alekhin, a complex and strategically interesting debut. The move 1...Kf6 was used in practice by the future world champion A. Alekhin in August 1921 in Zurich. Subsequently, Alekhin developed all the fundamental theoretical foundations of this beginning, and the defense that received his name was fully recognized. Many times they tried to refute the impudent attack of the black knight. However, in the end it was found that the sharp continuations are also associated with considerable danger for the attacking side. At the end of the book the most interesting games played with this opening are given. The work is intended for skilled chess players.