It's interesting to see inside George Lucas' mind

STAR WARS ORIGINALS: GEORGE LUCAS' IDEAS; WHILE MAKING EP5, GEORGE LUCAS HAD THE IDEA TO MAKE A RANKING SYSTEM FOR ALL THE FORCE USERS IN THE GALAXY USING NUMBERS. KENOBI WAS A 6, LUKE A 2, VADER 4, YODA UNKNOWN, AND EMPEROR GOING ON 10. THE PLOT FOR 5 WAS GOING TO BE STOPPING PALPATINE BEFORE HE GOT TO LEVEL 10, BECAUSE AT THAT POINT, HE WOULD BE INVINCIBLE. AND THEN OF COURSE, MIDICHLORIANS CAME AROUND AND GEORGE LUCAS GOT RID OF THAT IDEA.