Chess professor

The chess professor is a professor who taught Homer chess as a kid.

History
Homer and Grampa used to play chess every day. When Homer lost, Grampa used to laugh at him. When Homer got tired of this, he went and learned to play chess from a professor who lived nearby.

He told Homer that he reminds him of his son, who doesn't like chess. After Homer beat Grampa, Grampa stopped playing chess with him.