Can't disagree with anything that anyone has said.
You can certainly experiment with grappling in Chi Sau , one of my friends was an ex Hapkido guy turned Wing Chun and he was always trying to put me in arm locks from Chi Sau , usually it earned him a kick in the shins.
I've also used a particular arm drag takedown from Dos Pares , and also put people in arm locks , figure four etc. The thing to remember is that they are best applied when you have pivoted the opponent off to the side and you are on his blindside so that you have control of his nearside arm and his other arm is way out of range , slap it on real quick and be prepared to jam a low kick from his close leg as you put the pain on.
Don't even think about trying to apply them when you are both square on because while you are busy trying to set up the particular wrist lock or arm lock to immobilise his arm your eating 15 punches in the face or getting the crap kicked out of your legs.
With chokes and throws I've found that I can pierce through up past the neck with the Tan Sau and put people in a head/arm strangle then take down with a circle step sweep from Bil Jee and then into the knee ride position or full mount .
Or even go from Bong Sau into a headlock and sweep or throw etc.
So all the tools are already in there for you to penetrate their defences and get into grappling range , particularly using the Tan Sau and also the Bong Sau. Its just how far you want to take it.
The problem is that you can only make them work when someone is worse at Chi Sau than you , when they work they are great , but when they don't the penalty is too great.
If you try it on someone with greater skill in Chi Sau than you what happens is you either get pivoted off to the side and peppered with punches on your blind side , or you walk into an elbow or a punch , or end up getting trapped.
Trying it on a dude thats at a high level in Chi Sau is suicide , you can't get any purchase on his arms its like trying to grab smoke or water , you try to push his arm somewhere and his arm then becomes a trap or a strike.
I pretty much know as soon as I start doing Chi Sau with someone whether I can apply grappling concepts on them , usually they are using a lot of force and are very tense which means I have a fair chance of being able to parry their arm aside without eating an elbow in the face whilst getting body to body.
You have to have a pretty good idea that you can pull it off , there is a time and a place , you have to be able to gauge when that time and place is.
Another thing to remember is once you start to get into the realm of adding grappling to Wing Chun then you are starting to disobey one of the principles of Wing Chun which is the minimum use of brute strength.
Also the Wing Chun way of controlling and striking , using up to 3 limbs simultaneously to overwhelm the opponent as well as the projection of force from the stance to unbalance the opponent sort of makes grappling redundant .
Wing Chun is purely an aggressive self defence art , knock em down , drag em out , get the job done quick. The problem is with Wing Chun there is no setting your Phasers to stun.
Which is why I added grappling to my Wing Chun for those situations where it may not be appropriate for me to use pure Wing Chun and batter someones face in or maim them so that they will never walk properly again , you know like the drunken brother in law syndrome etc.
We have to have some way of handling these situations with compassion when a low level of aggression calls for a low level response such as a takedown , submission , or simply pinning them to the ground while we wait for them to calm down or for the police to arrive.
I trained with a Pancrase guy for a year in ground fighting and there is an element of strength involved , I know the grappling afficionados will say that they use leverage because that is true , but they don't use it in exactly the same way or to the extent that Wing Chun people do.
But if you can pierce through with your Tan Sau or Bong Sau then there is certainly scope to turn that striking opportunity into a grappling opportunity in the right circumstances. Which is why all Wing Chun people should really work on protecting their neck , I can't emphasise that enough.
If it looks like the opponents Tan Sau is getting up near your neck Pak sau that bugger away on the inside of his arm and simultaneously return fire to the low line with your other hand , I usually use a low horizontal palm strike to their ribcage.
Stay in contact with his Tan Sau or what ever is trying to capture your neck , convert your Pak and Lop sau his arm down and then punch over the top with your hand that was previously down low doing the palm strike. It really is a last ditch defence when the Tan sau is almost at your neck , you don't know whether its going to be a strike , a neck surround or even both .
What you really want to be able to do is to detect it at an earlier stage and take a small step back with one leg , as you simultaneously drop your Fook sau down on his Tan sau ( this latches him down , ruins his structure) whilst at the same time piercing forward with your own Tan sau , thus taking advantage of his compromised structure . Note. (step back on the same side as your Fook Sau )
So in essence the counter is pretty much the mirror image of the attack , except you are taking a small step back , dropping your Fook Sau down a tad and pulling him in to your own Tan sau pierce to his neck .
