it has not moved toward/away from either end zone).ĮDIT: Also, it should be noted that like anything in sports with human officiating, things are only relatively accurate. By following a yardline out onto the field, the offical can ensure that they have accurately moved the poles and that the 10-yard section they measure has not moved up or down the field (i.e.
He then holds the chain section on that spot on the field while the posts set themselves. Second, when officials need the poles and chain to come out on the field to measure, one of the officals will run over to the sideline, pick up a part of the chain that rests on a yard marker line, and follow that line out onto the field. Then, the other pole is simply moved out to its full length, marking ten yards. The rear marker pole is placed on this marker. First, when the ball is placed on the field at the line of scrimmage, a bright orange marker (shaped like an elongated pentagon) is placed on the sideline directly in line with the ball.
To synthesize the other two answers (and add a little extra clarity, I hope):Īside from the specific length of the chain/marker pole combination, there are a couple of things that the officals use to make sure they measure accurately.
