On one of the short 1x4 end rails, mark off a notch where players will stand to slide their pucks. Make marks 3 and 11 inches from the right end of the board. Then, measuring from the bottom edge of the 1x4, draw a line between the vertical marks at the thickness of the door—typically 1⅜ inches—so that the bottom of the notch will install flush with the door's surface. Using a jigsaw, cut out the notch and round off the protruding corners. Apply a coat of white paint to the sides and center rail.