Operators of two of the largest U.S. ticket marketplaces say they are seeing declines in orders for NFL games amid festering controversy over the national anthem. NFL ticket sales at TickPick slumped 17.9 percent this week compared with the prior week, their steepest decline since 2014, while sales at TicketCity plunged 31 percent. For pro football games in September, ticket sales at TicketCity are down 16 percent from a year ago. TickPick's NFL sales rose this month, but by the smallest margin since 2015. The vendors' data reflect tickets sold in the secondary market, as opposed to direct sales from...