One commenter mentioned to "try it and report back" and then removed it. I just wanted to say "trying it and reporting back" is exactly the spirit of this thread, so I will proceed in that spirit.
Now this thread is cookin'. Thanks to everyone who is talking so far.
@Jaani I think you're onto something in terms of fundamentals - there are conflicts in some of the basic ideas, and that is part of what I hoped this thread would create space to talk about.
This chatter is all accessing what I find interesting in the discussion and what my little video was (attempting to) get at.
Since I'm talking more about mechanics than teaching here (but there's a motion experiment in here), I wanted to just keep clarifying a few things that might not be obvious in my little video at the top of the chat. I am going to avoid talking about "swings" or "pulls" entirely for the purpose of this thread because people tend to mean different things and clearly have strong impressions one way or another based on what they think the words mean (in terms of actual motions).
Here are a few reasons why whether or not you are encoding CoG/CoM in your "model" for how it works matters. It's not just about imaginary pink orbs floating in space.
I found a diagonal kettlebell move useful for this. Take a kettlebell and let it swing down toward and just past the left foot, then take it all the way "targetward" down the line like the backhand (I still use arm action just like my backhand when I do this). If I go full on Clement (which is still how I mostly think about the posture-sequence connection and the way I prefer to talk about arms personally) I get closer to what I call Model 1. Heavy emphasis on CoG, clear centrifugally driven move, incredibly low effort and smooth acceleration out of the backswing. It's still athletic in a similar way a golf swing is (or at least, one model for a golf swing) and you can power it up like a golf swing with momentum and shifting and more "juice" from the plant up the chain. Power seems to mostly come from those sources.
If I instead make the motion the way I can do a diagonal kettlebell swings from just past my left foot near the floor to all the way "targetward" down the line using very similar arm mechanics and sequence and posture otherwise, the Model 2 throw is adding more emphasis and juice on the linear(ish) trajectory of the move. There's a little more emphasis on the braced "stop" of the move, and a little more coming through the "top line" of the move that some people might call "arming." But to me it is still just a very natural feeling and flow of actions from head to toe and toe to head. It is not just using the arm to yank - there is a clear contribution of shifting weight, and there is still centrifugal force/rotation/braced and balanced tilt of course. There is a point where I can
clearly take it too far and turn it into a shoulder "yank" over top of the brace that really isn't taking advantage of the motion efficiency of the body. Power comes from similar sources to Model 1, with a
potentially higher "peak" power due to the different in chain recruitment. Overall across the chain, I noticed that there is a slightly bigger emphasis on fascial loading and unloading and elasticity, and slightly smaller emphasis on the movement in the imaginary CoG.
Both model 1 and model 2 (for me) use "hollow body" posture. That is partly just saying that you are in athletic posture making space for the disc. That is where the disc comes through the imaginary CoM that Sidewinder likes to discuss. I didn't understand what the hell that was until a lot of drilling. I had to literally hold a cylindrical trashcan and walk around with it at one point. Forgive me because my athletic posture control and balance is still not as good as my Waltz posture control and balance, but the CoG/"hollow body" space are just (CoG is probably a little more East than this pic but I made it quickly):
But
to me, that hollow body space is
also related to organic movement and balance in the body that encode side bend, tilted axis, and related concepts and moves. Those are all concepts that directly cross over to dance training. That's why my motion in model 2 is still more "Simon like" than it is like trying to just yank the disc through my shoulder (which I used to do and it almost ruined my shoulder). I do not think everyone who is instructing views posture and posture control the same way (i.e., to me it is clear they do not, at least). When I watch Simon, I see profound - and probably unique - efficiency in motion that started when he was 2 years old. He went through a dramatic vertical and pendular phase of development. People who don't develop that way move differently than those who do. Or at least, they
always look that way to me now.
Obviously my motion pattern was/is highly influenced by
@sidewinder22 and swing and centrifugal efficiency theory and tons of (endless) dingle arms. I am very grateful for that and continue to learn from him. I think if I had started in the opposite direction more Model 2-y I would be getting hurt much more than I already have. By learning from him I have been able to safely explore these ideas in my own motion and find little differences in leverage points and weight shifting and sequence and so on. It is like walking through the cupboard into Narnia.
Now that I have increasing "motion fluency" and can change things "on the fly" faster, moving into more "model 2" mode is a potential space for power to fish around in. In my personal taste (both my own form
and coaching), I am going to look for the efficient version of the motion no matter what or how it is emphasized in the chain. I will always have physical limits to be aware of. There are still things to learn about sources of power. But I also suggest that there are some motions that can generate power at some cost to safety and/or that require more or different kinds of athleticism that are developed in different ways over very long periods of time. While I also obviously admire Simon's form, there are clear reasons I'll never move that well. On the other hand, if Model 1 and Model 2 are a continuum (differences in degrees rather than kinds of form), I probably want my chain to learn from both of them.
PS: I have someone from the "back leg throwing" perspective on my channel. I pinned the comment and discussion in the YouTube video at the start of this thread. I am trying to have an actual conversation with him. So far it is going well. It is possible to talk to people who see things differently than you if you try to understand what they are saying long enough and are patient to ask questions (sometimes, not always).