This season, the league contends that the number of concussions has been reduced, although the figures are not known.
The league, which said it would appeal the decision, had contended that Clarett had no legal standing to file the lawsuit.
The league has contended that the union's tax rates are too low to have an effect.
The league contends that any such venture would be prohibited by the collective bargaining agreement between the owners and the players.
The league has contended that such offers, intended to make one club pay more than another, violate the spirit of the labor agreement between management and players.
The league also contends that developers are prominent among contributors to the Kozakiewicz campaign.
The league contends it has sole discretion over how to redistribute money collected from luxury and escrow taxes.
The action does not constitute an unfair labor practice, the league contends, because it says it is for informational purposes only.
The league has contended that these issues will be decided only by collective bargaining no matter when the deal is finished.
The league contended that its clubs spent about 75% of revenues on salaries; a percentage far higher than existed in other North American sports.