When Rob Lytle died at age 56, three decades after his football stardom at the University of Michigan ended and his professional career with the Denver Broncos began, his son Kelly Lytle poured his mix of grief, adulation, regret, gratitude, and even criticism into a series of letters to the man he considered his best friend. What began as catharsis evolved into a memoir that starts strong and gains steam the way Rob Lytle did in his dashes down the...