Cirillo tagged 1st base on the grounder with the bases loaded ... okay, but don't the runners all have to still run on that play thereby making the play at home a force play? Why does making the throw to home after tagging first make the play at home a tag play as opposed to what would be a force play at home had Cirillo not tagged first base. The runner on 3rd had to run, regardless, didn't he? No, once there is a force, the baserunners are free to run wherever ahead of the force. By "forcing" the runner at first, Cirillo made everyone else a live runner. Think of it as if two runners were standing at a base in a rundown - they both can't be out, so one can be safe. That makes all the bases eligible for a "safe" call to be made on runners.