John Wooden was an American basketball player and head coach at the University of California at Los Angeles. Nicknamed the "Wizard of Westwood," he won ten NCAA national championships in a 12-year period as head coach at UCLA, including a record seven in a row. No other team has won more than two in a row. Wooden was renowned for his short, simple inspirational messages to his players, including his "Pyramid of Success." These often were directed at how to be a success in life as well as in basketball. Wooden's 29-year coaching career and overwhelmingly positive critical acclaim have created a legacy of great interest in not only sports, but in business, personal success, and organizational leadership as well. He is quoted in a book called The Intangibles of Leadership"
"A leader who is ruled by emotions, whose temperament is mercurial, produces a team whose trademark is the roller coaster - ups and down in performance; unpredictability and undependability in effort and concentration; one day good, the next day bad. Good judgment, common sense, and reason all fly out the window when emotion kicks down the door."
The chapter in which this quote appears ends with this sentence: "Master your emotional reactions, and use them to influence others."