The author developed a model that explains and predicts both longitudinal and cross-sectional variation in the output of major and minor creative products. The model first yields a mathematical equation that accounts for the empirical age curves, including contrasts across creative domains in the expected career trajectories. The model is then extended to account for individual differences in career trajectories, such as the longitudinal stability of cross-sectional variation and the differential placement of career landmarks (the ages at first, best, and last contribution). The theory is parsimonious in that it requires only two individual-difference parameters (initial creative potential and age at career onset) and two information-processing parameters (ideation and elaboration rates), plus a single principle (the equal-odds rule), to derive several precise predictions that cannot be generated by any alternative theory.