I´d like to start a new topic that rather belongs to the stance but I stand on my feet so I think it´s well posted here.
The point is were to put the most balance on?Some people say you have to turn on the heels,some say you must turn on the footbundel and some say most weight must be concentrated on the middle of the foot.
I think it´s very important to have the right idea because your stance and hence your stability and balance are depending to it.
I do believe we have to turn on the middle of the foot as well as we have to devide our weight 50 - 50 on our two legs.If you turn on your heels you are standing a little back leaned and you are feeling like you are standing on stalks.You have very low control of you balance while turning.
Besides try standing on on your heels centred within standing in a step.

The turned stance is standing in a step or called a "Ready for fight stance".
If you start getting into the ygkym you first bend your knees what means that you get a little deeper.
If you look down now your knees are covering your hole foot.Now you are balanced well and if you watch carefully you will notice that you can feel the pressure of your body is pressing your hole sole of the foot is pressed firm to the ground.If you are balanced on the heels you have a week and rocky stance.You can only feel the pressure point at your heels.Your floor space is 75 percent smaller than standing balanced on the middle of the foot.Everyone can test it on his own and should keep what works and leave what does not.
I think if you get pressed backward within chi sao you should let sink your weight a little more within your knees pointing towards your toes.
Now you are creating a strong forwarded force that´s directed properly to the ground.If you let sink your weight instead of counter pressing from below to above than nothing happens to your balance if the counter pressure suddenly dissapears.
