This is essentially a tutorial on how to make decisions on the doubling cube in backgammon. The book contains all the information about what the doubling cube is. history of its origin, the main provisions of the theory with a detailed analysis. Key concepts: odds, equity, MET. How to use tables. After reading the first part of the book, you will be able to fully understand the meaning of the doubling cube and will understand how and why the cube is placed or accepted. The second part of the book gives a new, author's approach to how to CALCULATE the correct solution for a cube. If you master the calculation of odds on the board at the moment and memorize the not at all complicated tables from this book, you will be able to master the doubling cube at a very high level, and after mastering the psychological subtleties of assessing your opponent’s capabilities, you will be able to claim the top level of mastery of the cube.