Just an intellectual curiosity from someone with a minor in History.

I was looking at the updates on my youtube subs and found the following video from Dennis Gempo Merzel Roshi:

"1 Introduction to Big Mind by Genpo Roshi"
http://www.youtube.com/watch?v=zT9y1YEUjy0[/video]]

I sortta remembered about "The Big Mind" from a Brad Warner's article. This time I decided to watch the whole set of youtube videos (ok...up to part 5 :P ).

I read the wiki articles on Big Mind and Dennis Genpo Merzel to get more background info. I also read Ken Wilber's intro to Big Mind/Big Heart by Genpo Roshi.

From Wilbur's text:
Let me state this as strongly as I can: the Big Mind Process (founded by Dennis Genpo Merzel Roshi) is arguably the most important and original discovery in the last two centuries of Buddhism. It is an astonishingly original, profound, and effective path for waking up, or seeing one’s True Nature. What Dennis Genpo Roshi has done is not only the most original discovery in Buddhism in the last two centuries, it is unbelievably simple, quick, and effective. In Zen, this realization of one’s True Nature, or Ultimate Reality, is called kensho or satori (“seeing into one’s True Nature,” or discovering Big Mind and Big Heart). It often takes five years or more of extremely difficult practice (I know, I’ve done it) in order for a profound satori to occur. With the Big Mind Process, a genuine kensho can occur in about an hour—seriously. Once you get it, you can do it virtually any time you wish, and almost instantaneously. It is nothing less than the discovery of your True and Unique Self, Ultimately Reality, the Ground of All Being—again, call it what you like, for “they call it Many which is really One.”
:shock:

But.

What I am trying to figure out is the connection from where Dennis Genpo Merzel the Zen Teacher went to become the Dennis Genpo Merzel the Big Mind teacher. To put it in another way, what is the Buddhist foundation or connection between Dennis Genpo Merzel's Zen Buddism and his Big Mind practice? I read the wiki article, but I can't see the connection.