Mayo points out that, while the Pirates' 2013 roster wasn't primarily homegrown, and that's an aspect of the Pirates' 2013 success that's really interesting. In 2007, Neal Huntington and company probably imagined that the next good Pirates team would be successful primarily because of the draft. Obviously, the Pirates got a lot of mileage in 2013 out of players like Andrew McCutchen, Starling Marte, Gerrit Cole and Neil Walker, but they also got more than they possibly could have imagined out of veteran acquisitions like A.J. Burnett, Francisco Liriano, Russell Martin, Jason Grilli and Mark Melancon. If the Pirates' success continues (and with the leaps forward the farm system has taken in the past two years, that obviously looks at least reasonably likely), that success will probably be fueled more by homegrown players.
Anyway, a lot of the specific praise for the farm system here will be familiar to most of us, but it's nice to see them ranked the very best by someone who knows what he's talking about.