Of course it's a skill - I think that's part of what Dan's saying.
Suppose you have a connection (and they, you) - then what? What comes into play, and why?
Well, that play back and forth is a big part of what it's all about, IMO. I mean if someone grabs me, my goal is to connect, control and/or throw. If I connect to them and start applying my strength to take control and they're able to connect back to me, then chances are they're going to find a spot to push me off my center at some point, if they can. They may not be able to though, even if they can connect back to me. There are so many potential layers to that back and forth based on the skill levels or disparity of skill levels.