Dai Vernon, considered among the most influential magicians of the 20th century, could do just about any trick that called for sleight of hand. He was obsessed with learning the secrets of crooked card dealers. But there was one move he couldn't master.
He's referring to the "center deal." He tracked down one of the few people who could do this deal and learned it himself. Then he video taped instructions on how to do the center deal. You can watch the 1982 video at the story site.
It's really a neat story.