Anti grappling is merely learning how to relax your limbs and make them very flexible so that when you do get grabbed they will not be there. What I mean by that is that they will feel like they slipped out of your hand and targeted your face. Wing Tzun training teaches your limbs to be like a strong spring. If you compress it and then let go it will spring back at you. If you compress it at a certain angle, it will eventually spring loose and smack you. In a similar fashion, the Wing Tzun practitioners limbs (arms and legs) act the same way. More advanced practitioners not only make their limbs this way, but also their entire body. They become very elusive and slippery when grabbed. A Wing Tzun person does not want to grapple because then he can't strike. That's why we do anti-grappling. Our forte is to strike when in close range. The grappler wants to get close and grapple to prevent strikes from hitting him, but he has to be careful with a good Wing Tzun person because he will likely have a hard time controlling him initially. If the WT person is stupid and starts playing the grapplers game, then he will loose. It takes lots of training and skill to be able to get good at anti-grappling skills. That mainly comes through the practice of chi sao and realistic training against attacks similar to what a grappler would attempt. Grapplers are tough and we realize that, but they aren't invinsible.