Ich habe Alvin mal dazu angeregt auf eure Kritik zu reagieren. Die Ausführungen sind etwas länger geraten, aber vielleicht doch ein sinnvolle Anregung für einige.

Wir sind übrigens Schüler von Guo Shilei. Der wurde hier glaube ich auch schon mal diskutiert.

"Hi, guys, glad you had fun watching some of the videos from my demo at the university. 😊 It's been suggested that I come in and explain why one of my demo partners bounced and the others (mostly) didn't.

First of all, as you can probably see, I'm just a novice and not any sort of master. Still, whatever little skill I have has been quite helpful in my interactions with people from other martial arts. I have played with many friends and strangers trained in BJJ, JKD, Judo, Kali, Muay Thai, Silat, and so on, and even using their rules (e.g., groundwork only) I've found my Bagua/Taiji training to be extremely useful.

https://www.youtube.com/watch?v=E3OI0sx4NyQ
Now, the bouncing. My partner in that demo was Chu, one of my juniors with a background in Muay Chaiya and Jeet Kune Do. He wasn't going all out to "get" me in that demo, but neither was he jumping out of respect or because of conditioning. Because of our training, we both have very springy bodies (pengjin), and what you get when two highly elastic bodies collide is that one or both bodies go flying.

Of course, this cannot happen (at least not to the same degree) when at least one of the bodies is inelastic, and so when we push with people without pengjin, they seldom go bouncing out. Instead, typically, their structures get crushed and they fold. Whether they are untrained in martial arts or trained in non-internal styles, this is the end result.

Anyway, the obvious question is: why do we express pengjin? It's certainly not so that we can bounce people out! The first answer is that pengjin is protective. The second is that it is the basis of our offence. Let me start with the latter.

As the formula goes, power is initated in the feet, generated by the legs, transformed by the waist, and expressed through the arms. But how can power be expressed through the arms if they are weak? And so we have pengjin, which is similar to (but not the same as) the modern engineering concept of tensegrity. A structure that spreads out forces evenly is one less likely to shift or collapse under load, and this is very useful when you are hitting someone or wielding a weapon.

A pengjin-backed hit does not waver and lose energy "sideways" and so is very efficient. It often passes into the body without leaving an external mark; the effect on the person is quite shocking. And it quite often crushes through the strongest blocks; we like to ask martial artists we have just met to try and parry or block our swing, and almost all the time our arm scythes through their guard and right into them. Pengjin hits are very "heavy" and even a very gentle one can stagger a person. In this video from last year, I demonstrate a very light swing on a participant and he is staggered despite blocking the strike [4:49 - 5:22].
https://youtu.be/XbMt9rwOVEc?t=289

Pengjin is even the foundation of our footwork. People often look at what we do and think they use the same angles and concepts, but I guarantee you that unless all their motions are also pengjin-based, that is absolutely incorrect.

The protective function of pengjin may not be immediately obvious, so I hope you will bear with me and allow me to talk about two different scenarios.

In the first scenario, the opponent also has pengjin. In this case, having pengjin allows you to stop or deflect his "unblockable" attacks. Of course our hits are not completely unblockable; they are just very hard to stop... unless you also have pengjin.

Pengjin is a direct result of having "transformed" tendons and fascia. While the muscles remain soft and relaxed, the collagenic structures of the body "expand" or "extend" into a rigid matrix. I have personally found this solidity to be highly advantageous in grappling; pengjin makes one almost impossible to put into a joint lock. When playing with Aikido, BJJ, and Judo teachers/competitors/black belts, pengjin allowed me to stop most of their techniques fairly easily.

And that is why we emphasize so strongly the idea of not "switching off" pengjin during any part of a fight. Having it on is a serious advantage. For instance, when when pushing with strangers without pengjin, as in several of the videos from this event, the opponent has little chance to get in close or move your centre of gravity.

https://www.youtube.com/watch?v=dd0owKTgntA
E.g., in this video, both the guys pushing with me are trying pretty hard to take me down. The first guy is literally twice my weight and much stronger than I am, and admittedly I got a shock and struggled quite a bit especially at the start! Still, when I calmed down and stopped trying to muscle him, I managed to find my centre again. With the second guy, it should be quite obvious that I didn't need to get serious at all.

https://www.youtube.com/watch?v=5gAZVG7dKuY
In this other push hands video that someone posted earlier, I even clowned around by standing on one foot at several points. Because of always-on pengjin and single-weightedness, there was no change in the force he was receiving from me even when I did that, and as you can see nothing he did had any effect on me.

This is not to say that we will definitely defeat any person trained in Aikido, BJJ, or Judo! We do have a special advantage but of course other factors such as weight, strength, and skill matter too."