Chip Kelly, Ryan Day and the early days of an American football revolution

DURHAM, N.H. — The Downeaster train whooshes northward on a fall afternoon, past lily-covered ponds, over rusted bridges and through the reds and yellows of the New England woods. Halfway between Boston and Portland, Maine, the train horn blasts, and the conductor hurries down the aisle, keys jangling at his hip. “Durham stop,” he calls out. “Durham.” The brakes squeal, and a college town comes into view.The railway cuts a path through the University of New Hampshire’s athletic campus. To the right, there’s an arena they call “The Whitt,” the crown jewel for a hockey school. Look out the window to the left, and the last thing you see before the train ducks beneath an underpass and stops in front of a small station are the goalposts and grandstands of the Wildcats’ football stadium.It feels a long way from big-time college football. But it was here where, a quarter century ago, two great offensive minds came together. Chip Kelly was a first-year offensive…