When the founders worried how students would be selected after their deaths , Godric Gryffindor took his hat off .
Founders each added knowledge to it , allowing the Sorting Hat to choose the students by judging each student 's qualities and placing them in the most appropriate house .
When the founders worried how students would be selected after their deaths , Godric Gryffindor took his hat off and they each added knowledge to it , allowing the Sorting Hat to choose the students by judging each student 's qualities and placing them in the most appropriate house .