With thrillers like Thief, Heat, and Miami Vice, filmmaker Michael Mann approached the "cops and robbers" genre from an askew angle, packing simple stories with romantic yearning, coded language, and odd tangents. So it's not a surprise that Ali, his version of a "sports movie" and a biopic starring Will Smith as the fighter, is an ambitious, occasionally strange clashing of tonalities. Instead of attempting to tell Ali's life story, Mann burrows into specific conflicts -- tension with religious leaders, a thorny relationship with the media, and a volatile love life -- and creates a fractured portrait of a national hero. If you're looking for a Rocky-like narrative, stay away. But if you're seeking something as complex as the fighter himself, step into the ring.