How are editors valuable to film directors? How can editing make or break a drama?

Editing is taking out the bad and slow and bad bits, and looking deeper into the good parts. However, it can be very difficult to decide what makes a scene effective, and what could ruin it - it could be only one frame. Professional editors have experience and knowledge of how to merge scenes, at exactly what point. Film editing is an art that can be used in many different ways; it can bring out the emotional truth in an actor's performance. It can provide a point of view. It can guide the telling and pace of a story. It can create the idea of danger when there is none or suprise when we least expect it.
Film Directors' roles are to influence the way a film is made, to direct actors in their roles and affect how the movie is filmed. Afterwards, there will be an excess of recorded films, of which the director will only want a small part of. Therefore, as a result of this unrendered film, Editors are responsible for pulling all elements of the story; dialogue, music, sound effects, visual effects, pace and rhythm of a film.
As a result of their great responsibilities, film editors can either make or break films. Nowadays, they have even more important responsibilities; editing roles have merged, such as picture editing and film editing have both now come under the film editors responsibility. Furthermore, their audience sizes have increased - leading to either greater success or failure. Moreover, film editing has become more intricate, because of the new technology, there are higher standards and more possibilities - which are harder to learn and gain experience from, but can give an even greater result than in the past.
Peter Trybus