Researchers compared the GPA of male students at Oregon with the results indicating a correlation between lower grades and the football team doing well. Remember correlation doesn't mean causation.
http://www.washingtonpost.com/sports/colleges/study-when-1-big-time-college-football-program-won-grades-for-male-students-dropped/2011/12/20/gIQA0cGX7O_story.html
http://www.washingtonpost.com/sports/colleges/study-when-1-big-time-college-football-program-won-grades-for-male-students-dropped/2011/12/20/gIQA0cGX7O_story.html
