Systems and methods for providing enhanced navigation of stored digital video content based upon an event index. Includes generation and storage of an event index, as well as navigation based on events in the event index. An example system is embodied in a digital video recorder that detects and stores black field and silent frame events for use in locating commercial groups. The commercial groups may be skipped or otherwise navigated based upon data pointers linking the stored events to corresponding locations in the video data file. Generation of the event index may involve comparing a luminance value for each frame to a luminance threshold value for a video presentation. The luminance threshold value may be based upon a transition point between a first group of luminance values corresponding to video content and a second group of luminance values corresponding to transition events, such as black fields.