Fair or foul???

[4 Sport Official]

Just think of the bag as the base of an imaginary fair pole/foul pole, for the purposes of batted balls that have been grounded. For all intensive purposes it works the same way as the "foul" pole, with the exception of a fair ball IN FLIGHT. Just picture what would happen if there were a 15" x 15" pillar rising up from the ground where the bag is located up to the heavens. Would the bounding ball have contacted this imaginary pillar? DING!!! Fair ball.