Bert Marcus on his Knockout Documentary Champs

As star-studded as the front row of any primetime heavyweight fight, the boxing doc Champs calls on A-listers from Mark Wahlberg and Ron Howard to Denzel Washington and Mary J. Blige to weigh in on one of the most brutal sports in history. Beautifully shot reenactments and first-hand stories are interspersed with real footage of some of the most famous brawls of all-time, making for a riveting ride. But this isn't just any sports documentary —