OBS at home - how do you know?

[CecilOne]

As with any rule change, there are always some officials who will go to the extreme, as in Celtic's reference to NCAA and Jeff Hanson. But that, usually, and in this case means paying more attention to the change than the full rule. Which means calling OBS whenever a base line/path is blocked without possession of the ball, ignoring that the rule requires the runner to be impeded.

Therefore, "call OBS only if it is a visible alteration in the runner's path " AND the fielder causes the alteration (i.e., impedes) without possessing the ball.

In my mind, that does not have a distance restriction.