An inspirational documentary on the highs and lows of an inner-city football team might not sound like the most appetizing moviegoing choice. It’s a sufficiently kneaded topic to cover, yet “Undefeated” displays more vulnerability than most films of its ilk, searching to understand how young men facing countless physical, financial, and educational challenges manage to band together and find a common goal. “Undefeated” dissects the interpersonal dynamic of the unit and the near-spiritual nature of the coaching position, covering a single season in the life of the Manassas Tigers as the squad looks to reverse a losing trend that’s swallowed the morale of the school and its surrounding community. Read the rest at Blu-ray.com