I doubt it can be nailed down to any thing that is exact. I agree it varies from dog to dog, and could mean just about anything. The one thing that seems to be consistent is intensity. The dogs that knot and fuzz seem to get jacked (geeked) faster, deeper and maintain the intensity for a longer duration. Does the intensity mean gameness? Not in the least. From my experiences it just seems it is a sign they get real focused and really, really what is out in front of them. Now how long they want what is in front of them after they get it, well, that is a completely different ball game. EWO