You see I always viewed the OT as a three act play. This may be that I was born by the time they were all out, but the three create one cohesive story. In any play you can usually catch a solid feeling in the first act, and the third, but just watching the middle creates confusion because it rarely has the meat of the plot. It;s part in the plot is only truly realized when placed in its proper place amongst the rest of the play. The second act is normally everything going wrong for the characters you are taught to love and care about. For a three act play perspective Empire Strikes Back does a phenomenal job as a second act. As a stand alone story it flounders, but to do what it does I have rarely seen anything as good as it.