Yeah hi there, welcome.

Hmmm Grand master 'was' taken as the inherant eldest master member of any kung fu style.
Yip Man was such a man.
Wing Chun ws always a guarded style passed onto only a few and only the chosen of some familys got the whole style passsed to them Yip man was also one of these.
Through him, wing Chun split into two schools (the closed footwork nose to nose traditional style and the more fluent wider footwork style which included all the switching techniques and angles for simultanous attack defence etc.
This occured through the jelousy his full blooded Chinese students had against William Cheung his fully adopted student and Bruce Lee (half blood) his famous movie star friend who was getting a hiding on the streets from thugs prior to and in the days of the green dragon seris etc.Bruce was tested out by all types once he got famous.But he was just a kicker like a ballet dancer pretending at that stage.
Yip man was only supported financially, by his students in Hong Kong and lived above where they trained ,funded by the meagure fees.
Bruce was a natural and would fight off other wing Chun opponents years ahead of himself. This is what caused the riff in the whole system.

And the reason why Yip mans own blood son and the German sector of wing Chun in paticular have the stilted footwork as their base.

Yip man explained to William that his students had put an ultimatum to him that he expel Bruce cause of his half blood and that wing chun was always protected nationally and should only be passed onto full bloods.

The Grand master was pissed a this,he loved having Bruce around and the fame etc etc,so he trained William and Bruce using the full system of wing chun in spite of his students.He was going to pass this information on to only one person (his blood son as had nearly always occured in China) ,but his son sided with the others against Bruce.
So William and Bruce were taught the whole system after hours and william took the knowledge to Bruce after /after hours;(no secrects were held within one family as had happened for years in the system).
Thus Bruce's mind went on to create Jeet Kune DO.
This is all from Williams own mouth by the way.
There is more to it, but that is it in a nut shell.
He spoke of many fights concerning the local mafia and many challenges from other stylists as well as their own style, once word got out they had something else to add to it!
They kept thier side of the promise and never released it or taught it to westeners until after Yip mans death.
Yip man was the chief of police until the take over and then found himself on the streets.
That is why he was in a procarious position financially whlie taeching in Hong Kong in his later years.

William Cheung claims Grand Master status as he is the only surviving person who has been told the full system of wing chun.

There is so many students of all styles these days that the old schoolers have died off.

Now the term Grand master is abused in some sectors not used in its correct context.
There is no more real secrets either, as styles blend into others etc so who can claim grand master of anything?

Regards Andre.