( you can see a short clip of a couple guys working with circle to center here, scroll down a little, it's the second video clip. you should be able to view without being logged in.circle with center)
I'm missing the point. Sam is using jin. The other guy doesn't know how to use jin. Sam is not very clear in explaining it, so I expect it will be a long time before the jin concept is understood.
In terms of "tension" and all that, I think it's an interesting topic and it's a good way to go down a path toward muscle-jin. But then, having offered that good advice, I think I'm going to start taking Dan's advice and just let people I don't know do what they want to do. Wasting a few years is just part of the learning process.