Rule of Thirds.

This is a basic design principle that every photographer, painter or designer learns in their first few intro classes at school. The rule states that an image should be imagined as divided into nine equal parts by two equally-spaced horizontal lines and two equally-spaced vertical lines, and that important compositional elements should be placed along these lines or their intersections. Most professors pound in to their student's heads to the point where it becomes almost impossible for a budding artist to even purposely break the tenet, lest they be judged by their teachers and peers. Every once in a while though, you have to bend the rules just a little. A Rule of Thirds loophole if you will.