Earlier this decade, Jimmy Rollins, Chase Utley, Ryan Howard and Cole Hamels were minor-leaguers in the Phillies' system. They developed into major-leaguers and eventually formed part of the core that helped the Phillies win the 2008 World Series.
Rollins, Utley, Howard and Hamels exemplify why a minor-league system exists - to ultimately help the big-league club win games.
But a minor-league system isn't successful only when it sends productive players to the majors. Sometimes a minor-league system does its job when it helps a club acquire established big-league talent in trades.
That's why it can be argued that the Phillies' 2009 minor-league season became a success on July 29, the day the team sent four young players to Cleveland for Cliff Lee, the 2008 American League Cy Young winner.