The baseball documentary THIS OLD CUB chronicles the life and times of beloved Chicago Cubs third baseman and broadcaster Ron Santo, and was directed by Santo's son Jeff. Despite being diagnosed with a particularly dangerous form of diabetes as a child, Santo grew up to become one of the mainstays of the Cubs teams in the 1960s and early '70s. After his playing career, he became a fan favorite broadcaster for the team. But during both his years on the field and afterwards, he struggled to keep his diabetes under control, until finally it required both of his legs to be amputated. Combining footage of Santo in his playing days, in the broadcast booth, and during his medical difficulties with interviews with his baseball contemporaries and celebrity Cubs fans, THIS OLD CUB is an in-depth portrait that goes beyond the myth making of typical sports documentaries.