Concerned by growing uneasiness among fans and marketers about athletes gone wild, the league is embarking on an effort to burnish its brand image by accentuating the positive aspects of the on- and off-field lives of its players. In a television and online campaign that is to begin Thursday, the league and its advertising agency, BBDO Worldwide, are borrowing the playbook, so to speak, of industries like Big Oil and the big drug companies, which have relied on the magic of Madison Avenue to redeem their public images. The NFL's idea is to counter the outcry over the criminal behavior of some players, not by apologizing for the misdeeds of a few but by shining a spotlight on what is presented as the good behavior of the many. "It's as simple as this," said Lisa Baird, NFL senior vice president for marketing in New York. "We're going to do everything necessary to protect the strength of our brand."