Conversation so far:
How did John Heisman begin coaching?
John Heisman first coached at Oberlin College.
Was John Heisman successful at Oberlin?
In 1892, The Oberlin Review wrote: Mr. (John) Heisman has entirely remade our football. He has taught us scientific football.“
Why was John Heisman's coaching at Oberlin College called scientific?
John Heisman used the double pass, from tackle to halfback, and moved his quarterback to the safety position on defense.

Question: Why did he leave Oberlin?
Self-contained rewrite: Why did John Heisman leave Oberlin College?