Best perspective

From Ultipedia

Best perspective is an official term defined in the UPA_Rules_of_Ultimate.

From the 10th Edition UPA Rules - 'Best perspective' is the most complete viewpoint available by a player that includes the relative positions of the disc, ground, players and line markers involved in the play. Best perspective on an unlined field may require sighting from one field marker to another.

The phrase 'Best perspective' does appear in the WFDF_Rules_of_Ultimate, but is not officially defined.