Wolf and Bruhn had to convince the medical establishment to think about health and heart attacks in an entirely new way: they had to get them to realize that they wouldn't be able to understand why someone was healthy if all they did was think about an individual's personal choices or actions in isolation. They had to look beyond the individual." Introduction, p. 10.

The more he looked, the more Barnsley came to believe that what he was seeing was not a chance occurrence but an iron law of Canadian hockey: in any elite group of hockey players--the very best of the best--40 percent of the players will have been born between January and March, 30 percent between April and June, 20 percent between July and September, and 10 percent between October and December." Chapter 1, p. 22.

The idea that excellence at performing a complex task requires a critical minimum level of practice surfaces again...