Here is an excerpt from Pete Carroll’s WIKI page. Go there for the full story.
On offense, Carroll is known for using an aggressive, nonconservative play-calling that is open to trick plays as well as “going for it” on 4th down instead of punting the ball away. <#cite_note-ESPN080907-56> Because of his aggressive style, the USC Band has given him the nickname “Big Balls Pete.” At football games, when Pete Carroll decides to go for it on 4th down, the USC band will start a chant of “Big Balls Pete” that carries over to the students section and the alumni. <#cite_note-LAT082607a-57> <#cite_note-LAT102207-58>  <#cite_note-Esq09-4>
On defense, Carroll favors a bend-but-don’t-break scheme of preventing the big plays: allowing opposing teams to get small yardage but trying to keep the plays in front of his defenders. <#cite_note-LAT092207-59>
Carroll draws coaching inspiration from the 1974 book The Inner Game of Tennis, by tennis coach W. Timothy Gallwey </wiki/W._Timothy_Gallwey> , which he picked up as graduate student at the University of the Pacific; he summarizes the philosophy he took from the book as “all about clearing the clutter in the interactions between your conscious and subconscious mind” enabled “Through superior practice and a clear approach. Focus, clarity and belief in yourself are what allows you to express your ability without discursive thoughts and concerns.” <#cite_note-LAT082607-60> He wrote a foreword </wiki/Foreword> for a later edition, noting that athletes “must clear their minds of all confusion and earn the ability to let themselves play freely.” <#cite_note-NYT110208-21> He also cites influences frompsychologists </wiki/Psychologist> Abraham Maslow </wiki/Abraham_Maslow> andCarl Jung </wiki/Carl_Jung> , Buddhist </wiki/Buddhism> meditation</wiki/Meditation> master Chögyam Trungpa </wiki/Ch%C3%B6gyam_Trungpa> andZen </wiki/Zen> master D. T. Suzuki </wiki/D._T._Suzuki> . <#cite_note-Esq09-4>