The darkest day in NFL history began with several Philadelphia Eagles players arriving at Veterans Stadium at midnight, some 13 hours before the scheduled kickoff of a game against the Chicago Bears. They weren’t there to play; they were there precisely not to play. More specifically, they were there to stand sentry at all of the stadium’s entrances, where they would be picketing against the ragtag group of bartenders, firefighters, and insurance salesmen that the owners had hired to take the field in their place. It was Oct. 4, 1987—Week 4 of the NFL season. The league and the NFL Players Association were unable to come to terms on a new collective bargaining agreement by the end of August, and the players had authorized a strike that began Sept. 22, just after the end of Week 2. The strike—the league’s second in six years—wound up wiping out Week 3. The players wanted the right to free agency, in addition to better better pension benefits, severance, and the elimination of artificial turf. The NFL’s free agency system at that time required compensation to go to a player’s former team, which had a chilling effect on player movement and, in turn, on…