Shake has three tracking nodes: Tracker, Stabilize, and MatchMove.
The reference pattern defines a small pattern that will be searched for in subsequent frames; the search region is the maximum amount your tracking point will move between frames.
The tracker works best with a high-contrast reference pattern.
The Average tracks function enables you to combine multiple tracks.
Offset Tracking is used when your reference pattern becomes obscured. In this mode, the track point follows the same path, but a new search region/reference pattern is used to acquire the tracking data.