Walter Murch

Murch says that there are six different factors to consider when making a cut and getting it 100 percent.  They are:

 Emotion (51%) — Does the cut reflect what the editor believes the audience should be feeling at that moment?

Story (23%) — Does the cut advance the story?

Rhythm (10%) —Does the cut occur "at a moment that is rhythmically interesting and 'right'"

Eye-trace (7%) — Does the cut pay respect to "the location and movement of the audience's focus of interest within the frame"

Two-dimensional plane of the screen (5%) — Does the cut respect the 180 degree rule?

Three-dimensional space of action (4%) — Is the cut true to the physical/spatial relationships within the audience.