And we go by that philosophy on our HS crew as well. Only one coach ever raised heck when a play ended and noone blew their whistle. He asked, "as part of your job, aren't you supposed to blow your whistle when the play ends?" I answered, "as a part of your job, aren't you supposed to teach the players to recognize when the play's over? Oh yeah, apparently you've done a great job because they recognized that play just ended without our whistles." He was VERY VERY quiet the rest of the game.