Cid,
I think (not positive, because not all regions have the exact same policies for playoff seeding) that for most SCHSL regions, preseason games only "count" if two teams are tied in all other respects; first region play...if they are tied in region record and split head to head then it goes to regular-season out-of-region record; if still tied, then preseason and invitational tournament records can be used as a tiebreaker.