If the Chiefs can blitzkrieg opponents as they did in the playoffs last year, they may find themselves on their way to changing the game of football. A new National Football League season kicks off this week, after a turbulent and eventful offseason. During the last seven months, two national stories dominated the football headlines: The coronavirus outbreak and its effects, and the summer’s protests over race and policing. Both will affect the season, with fan-less stadia and player protests likely to continue.On the field, however, two stories will resonate. Tom Brady’s offseason decision to leave the New England Patriots...