Don Zimmer, and it’s not even close. He did the least with the most and did it consistently for five years. ‘78 was an abomination. His mishandling of… everything was quite possibly the single worst managing year in the history of baseball. Valentine was a clown, Hobson managed a team with very little talent, and Jimy was an uninspired choice who stayed too long, not his fault. But Zimmer nearly ran the franchise into the ground with one of the better rosters of the past 50 years.