Calling a high quality HS tourney in KY, MY Partner, PU, pointed fair, on a low pop fly ball towards 1st base. F1, F2 & batter/runner all running toward what seemed like the same spot and a sure train wreck about to happed. Some how. no contact, B/R made it to 1B unscaved and untouched. No one touched the ball. Ball landed and rested left of the line so PU signals fair ball. We know the rest of the story...................wrong line. PU proceeds to explain to the def/coach, that we seldom see running lane lines "at home", and assumed that the running lane line must have been the foul line. We fixed it.