Drew Carter was about to embark on one of the great traditions in Boston sports when the inspiration struck him to participate in another.
Carter, the Celtics’ play-by-play voice on NBC Sports Boston, is running the Boston Marathon to benefit the Shamrock Foundation, a Celtics program designed to support children in need.
The idea came to him, he said, while he was getting ready to board the duck boats at TD Garden for the Celtics’ championship parade in June.
“We were on the floor level of the Garden about to head out for the parade,” said Carter, “and I told my friend Dave Hoffman [the Celtics’ senior vice president of community engagement who oversees the Shamrock Foundation], ‘Hey, I think it’d be pretty cool to run it.