INDIANAPOLIS — That much-anticipated opening Thursday of March Madness will belong to the play-in teams, part of a scrambled and modestly condensed schedule for the 2021 tournament released Tuesday. The coronavirus pandemic forced the NCAA to move the entire 67-game tournament to Indiana, which means the schedule doesn’t have to be built with travel concerns in mind. The so-called “First Four” — two games pitting the last four at-large teams in the field and another two featuring the lowest-rated conference champions — will take place on Thursday, March 18. That day typically would have marked the start of play in the main bracket.