Mark Cuban, the owner of the Dallas Mavericks, said Tuesday night that he had instructed the team to stop playing the national anthem before its home games this season. “It was my decision, and I made it in November,” Cuban said. He declined to comment further. The Mavericks did not announce the new policy, but Cuban was allowed to enact it because the N.B.A. has permitted teams “to run their pregame operations as they see fit” because of “the unique circumstances this season,” according to a league spokesman.