This paper evaluates which variables, among those that are more understandable for an athlete, are predictors of jump height with countermovement (CMJ). Twelve amateur volleyball players (24.5 ± 2.7 years; 1.85 ± 0.6 m; 80.3 ± 5.2 kg; mean ± SD) participated in the study. The relationships between 15 kinematic variables and jump height were evaluated using Spearman's correlation coefficients. With a multivariate regression model, it was determined that the maximum knee extension velocity and the transition time are the independent predictors. It was concluded that the knee extension speed is the most important factor for the height of the jump. Changes within the range tolerated for knee action, could affect the evaluations based on the maximum height of the CMJ.