With an eye to the concept of 'brain drain', the chart below looks at how many active Hall of Fame coaches there have been in the NFL
from 1985 to 2015. The number has reduced over the years from six in 1985 to just one (future) Hall of Famer in 2015 - Bill Belichick. The infographic also shows the 'best of the rest' for each year as assessed by Greg Bedard of Sports Illustrated.
The full feature on this graphic can be read on Sports Illustrated