Over the last six months, I have tried to logically cover most of the structural issues in the application of tactics. It is easy to see that many of these issues are not black and white in application, but in fact a smoky grey based on environment and reality. I'll close the series with a cross section of information detailing what goes wrong when tactics are applied based on following thousands of people though tactical simulators and applying them myself on occasion.
There is a physical plane that should be considered when applying tactics either in the vertical or horizontal that works on the premise that no part of the moving gun platform (you) should break the plane being cleared before the correct time. As an illustration, a right-handed shooter should keep the plane in mind, so that no part of the gun platform enters the plane before another. If, while moving to clear a vertical corner, the foot of the gun platform breaks the plane first, the shooter, in projecting his foot into the area being cleared before he is in fact ready to clear the corner, creates a life-threatening problem.
In layman's terms the muzzle or body part exposed "leads" into the area being cleared giving your opponent time to prepare for the arrival of a target--you. This alignment plane of eye, muzzle and body should keep 99 percent of the body behind available cover and allow the eye behind the weapon's muzzle to roll into the area to confirm the area is clear or engage the target as may be required.
I am not exactly sure where this comes from. but after many years I think the enemy may be the one-dimensional target-range drill. The problem: When visual contact is made with the target the shooter often steps more deeply into the threat area than is required to make the shot, hence making them more of a target to the threat.
A couple of points. Most folks want to square up with the target because they shoot that way on the range in training. Targets at oblique angles often seem to cause more trouble for shooters than the straight-on ones do. I also think when we are in trouble the inclination is to step in and go for it, most often because we are not programmed in training to understand the threat can--and will--shoot back. A standard verbal response from me is, "How much of the target can you see?" The student answers, "All of him." Then from me comes, "How much of you can the target see?" The student answers, "All of me ... #@&*!"...