closely guarded

[observer]

Seems as if officials, NFHS/NCAA have different
thoughts on "closely guarded" distances. All seem
to know the 3-foot/6-foot count, but, is it measured
from offensive foot to defensive foot, torso to torso,
arm to arm, body to body, etc.
I have seen officials counting when a defensive arm
goes up and then stop the count when defensive arm
goes down.
Thoughts/comments/suggestions?