by Bretman » Sat Aug 07, 2010 9:09 pm
Picture a three-dimensional projection of third base straight up, to an infinite height, exactly the same square shape as the base.
A batted ball that first touches nothing but the ground before passing third base, then nicks any portion of that vertical projection as it passes the base, is a fair ball- no matter where it lands after that. That's any portion of the ball, no matter how small, touching any portion of that projection, no matter how small.
Was this a foul ball? Beats me. No possible way of telling without seeing it. But just going from your description, I couldn't rule out the possibility that it could be fair.