You’ve seen it before; a sweep comes to the sideline and the ball carrier and several other players go crashing out of bounds while the chain gang drops their equipment and runs for their lives. With the advent of instant replay, we’ve seen the chains set for a new series, but replay over-rules the call and the chains have to go back to their old position. How does the chain gang and the head linesman reset the chains after they are moved?
The chain gang uses what is called a clip. On the clip is a dial that has the numbers five through 50 in increments of five. On the dial is a clip that attaches to the chain links. The chains are, of course, 10-yards long so at least one yard stripe will always intersect the chain. The chain gang takes the clip, and attaches the clip at the back of the stripe. For instance, if it is first and 10 from the 21-yard line going out, the chain gang attaches the clip on the 25-yard line at the back of the stripe (so it is more accurate) and dials the clip so it shows the number 25. There is one man on the chain gang dedicated to maintaining the clip. He notes the clip’s yard line every new series. When the referee calls for a measurement, the head linesman jogs the chains out to the spot of the measurement and, in this instance, places the clip on the back side of the 25-yard line. Once the measurement is over, the head linesman resets the chain if it’s not a first down, or the chain gang sets the chains on the new spot, and the “clip man” places a second clip at the proper spot and notes the new yard line.
That’s all well and good, but what happens when there’s a first down, but instant replay over-rules the call and the chains have to be reset to the old line to gain? In the NFL and NCAA, two leagues that use instant replay, the chain gang uses two, sometimes three clips. When there is a new series, the clip man clips a second clip to the new yard line, and momentarily leaves the “old” clip attached to the chain. If instant replay or some other situation calls the chains back to the old position, the clip man and head linesman consults the clip man’s notes as to what yard line the old clip was on, returns the old clip to its proper stripe, and the chains stretch out. Once a play is run and the previous play cannot be reviewed, the clip man removes the old clip.
This clip is vital to fix the line to gain at a constant point. The chain gang goes off of the head linesman on where to set the chain stakes on a new series. While it may not be accurate to the millimeter, every NFL field is very accurately marked and the head linesman and chain gang are pretty darn close in setting the stakes accurately every first down.
While quite a lengthy explanation, the chain clips are quite a simple and accurate system in keep the line to gain a constant point on every series.
How does the chain gang line the sticks up to exactly where the tip of the football is on the field after a first down without having to measure every set of downs? Football is a game of inches and it always seems like some inches are lost or gained with these estimated placements. Using lasers would probably greatly improve the accuracy of placement, don’t you think?
When the head linesman marks the spot at the beginning of a series, the chain crew just needs to line up to that. Depending if the HL initially had the spot, his foot is the spot, even though the ball might be off that spot by a fraction. If he isn’t initially on the spot, he is very close.
However, the purpose that the chains serve is not that the team goes 10.0000 yards (although the length of the chain is exactly 360 feet), but that when the 10-yard chain is extended, that first-down post is constant. So, the measurement is to see that the ball made it to the point deemed to be first down. When they bring the sticks on the field it is to see if the offense made it past the post exactly where it was set at the snap on 1st down.
Being part of the chain crew for the NFL, most times when the ball is set, its on a short yard line. ie: 31,32, etc. When a team is driving inside the red zone, or “dives for a short 1st down, the ball is spotted where it lands. Having the short yard lines in the middle of the field and on the sidelines, helps to get the spot correct.
Ben is correct about the number of clips used. Sometimes in a Hurry Up, we use more then 3
Also, the LOS is written down every play along with the distance to a 1st down. There are back-ups to the back-ups
A great deal of thanks for an inside perspective! Let me give credit where it is due: Mark wrote the post, so he was the one who reported on the number of clips. I never realized that until now.
The clips I always get have a 55 yard line too. 🙂