Harrington, who has coach at College of the Canyons, Occidental and Hart High School, is enjoying a high: in his fifth year, he's 9-0 for the first time since he arrived.
The success to Harrington's cerebral approach to offense can be seen every Sunday in the NFL.
He coached Raiders quarterback Kyle Bowler and Carolina's Matt Moore.
He taught them what he's now preaching to his young players, that team success takes precedence over individual success.
"A lot of us have been together for four years, so we're really close, we're like a family," said senior wide receiver Shane Drozdowski. "We just all bonded."
What is Harrington most proud of?
"The number of kids, we have 50 more kids in the program playing football here at Alemany," he said. "And the way they conduct themselves on the field."