A computing system enhances the human-like realism of computer opponents in racing-type games and other motion-related games. The computing system observes multiple prescribed motion lines and computes switching probabilities attributed to switching of simulated motion of a racer from one prescribed motion line to another. A sampling module samples at random over the switching probabilities to select one of the switching probabilities. At least one control signal is generated to switch simulated motion of the entity in a virtual reality environment from the first prescribed motion line to one of the other prescribed motion lines, in accordance with the selected one of the switching probabilities.