This field is the average, as frozen at the moment this historical snapshot was taken, of the per-interval delta values for frames that were dropped because they experienced too many collisions (the classic 16-attempt limit) before ever being transmitted successfully, taken across the retained collection history for this stats object. Admins watch this to separate a genuinely sustained problem from one noisy interval — if DeltaAvg for excessCollision on this interface is climbing, seeing this counter increase on this interface is a reliable indicator of a duplex mismatch or an overloaded half-duplex segment somewhere in the path, rather than a one-off spike. For example, an average of 0 frames per interval sustained over many polling cycles points at a chronic issue rather than a one-time glitch.