Dallas Green.
Jim Frey Outlasts Another One
Killing a New Tradition
I feel that, had the Cubs had better ownership, Dallas Green would've been Theo Epstein 30 years sooner. He very effectively built a Cubs farm system that, in a few short years, delivered some incredible, Hall-of-Fame level players who naturally played their best seasons with other teams after Jim Frey decimated the future by making a series of lopsided trades.
Most importantly, he gave us Lee Elia.
He also acquired five Hall of Famers.