a "show off" item
used by certain checkair-persons whenever they have to start digging a bit deeper to score some points of self-confirmation when lacking in areas that count.
one should be able to look at said build up and within "seconds" determine whether one should go around or can go over.
same persons using this technique should come to same conclusion that is arrived at with "raw data" eyes.
if not, natural cause and effect should weed them out of genetic pool or if gracious, instruct them.