Duke University’s 85-81 overtime loss to the University of Kansas Sunday night meant more than just one of the nation’s top teams getting abruptly knocked out of the NCAA Tournament. It signaled the official end to the collegiate career of the most polarizing figure in amateur sports, Grayson Allen.

The college basketball world was stunned Monday night as Villanova University’s Kris Jenkins hit a championship-winning 3-pointer as time expired to propel the Wildcats to their first national title...