Son of a Boston Irish cop, Kevin Kelly grew up in Hyde Park. After his mother's tragic death, he and his brother found stability through their father, friends, a loving stepmother, and football. Following his brother's footsteps to Don Bosco High, Kelly nearly quit football. He was persuaded to stay by his brother's warning that he would regret it for life. Inspired by coach Jack Dempsey, the undersized team won the Catholic Conference Championship, a victory that led Kelly to play at the college and semi-pro levels. He and Dempsey later played side-by-side, winning a second championship and solidifying a lifelong bond. When Don Bosco closed in 1998, Kelly felt compelled to write their story to preserve the team's legacy and to understand how his mentor could "turn out to be so bad." Though writing was a 17-year "herculean task" for him, he believed the story needed to be told.

Today, Kelly passes on Dempsey's philosophy that desire and technique trump size. After running his own construction company, Kelly earned a Master of Education from UMass and switched careers to education administration, serving as a Principal and later as Assistant Dean of Students at Deerfield Academy. He has coached football at various levels since 1980. Kelly holds an undergraduate degree in Special Education and is married to his wife, Xiaofeng, with whom he has two daughters.