It’s not only the skills a Nobel laureate imparts to his pupils that makes them future winners, but the quality of those pupils that win the competition for such an apprenticeship, and the political advantage gained by the high-prestige association—notwithstanding Nobel prizes being often awarded after most of the mentoring has already been done.
That said, 30% (or 50%) is enough to support your argument. I doubt that most Nobel winners are genius talent evaluators, and I doubt that winning a Nobel is all politics.
I’d like RSS feeds please (for http://www.google.com/reader).