TrackingNet SUC is a quantitative performance metric in computer vision that measures how accurately and reliably a visual tracking algorithm tracks target objects across the large-scale TrackingNet benchmark dataset. Calculated as the area under the curve of a success plot, it reflects the percentage of video frames in which the intersection over union overlap between the predicted bounding box and the ground truth bounding box meets or exceeds varying thresholds from zero to one. By averaging these overlap rates across the entire test set, this metric provides a standardized overall score representing a tracking model localization precision, robustness, and ability to handle diverse real-world tracking challenges.