A method, computing device, and non-transitory computer readable storage medium are disclosed for probabilistically generating individually customized cognitive training sessions. A probability calculator executing on a computing device determines user data, priorities, and game data. The probability calculator calculates initial probabilities that a neurocognitive game will appear in a session, where the session includes neurocognitive games selected for presentation to a user (e.g., on a specific day), the calculating based on the user data, the priorities, and the game data. The probability calculator communicates, to a game selector, the initial probabilities, the game data, and a matrix controlling how likely neurocognitive games will appear in the session. The game selector selects a set of neurocognitive games for the session, where the selecting is based on the initial probabilities, the game data, and the matrix.