What takes concentration is aiming at something with no discernable marks. A new 3D target is a good example (and if you say you're aiming at the 10 ring....you can't see that from 20 yds....trust me). A deer is another.

It takes concentration.....but there is NO spot to aim at. I would have to assume that a deer with no tuft or discerbale mark would get a free pass form a lot of you guys.