Wednesday, September 21, 2011

First Down Measuring Mechanics

Have you watched the officials measure for a first down and wonder how they can be sure they got the measurement right?  Today’s lesson explains just how this is accomplished.
First, let’s start with how the chains are set up.  We have already learned about the chains, the apparatus handled by the chain crew, which is supervised by the head linesman.   When a team starts its drive, or gains a new first down, the head linesman has one end of the chains placed at the yard line where the ball is (the “spot”) and the other end stretched out the full ten yards, to the Line to Gain.  When I was an official for youth and high school, the head linesman would stand at the sideline with one foot planted at the spot.  A member of the chain crew would place his end of the chain (attached to a stick, or marker) at the head linesman’s heel and drag it back two feet, so the chain and its markers weren’t right at the sideline.
Once the chains are set, the head linesman takes a yard marker and attaches it to a link on the chain at one of the painted 5-yard lines on the field between the two markers (e.g., the 20, 25 or 30 yard line).  Here is a picture of what my yard marker looked like: 

As you can see, the marker has a clip that attaches it to the chain; the rest of it is a rotating dial and you turn the dial to the yard line where the marker is placed.
The yard marker serves two functions:  (1) to help the officials keep it in the right spot for a measurement (explained below); and (2) to let the head linesman know where to replace the chain in case the chain gang has to drop their markers to avoid being hit by a player coming out of bounds.
Now for the mechanics of making the measurement to see if the offense earned a first down… Please note that I'll be describing what I learned when training for youth and high school football.  The NFL officials might have a different procedure, such as who does what, but I can't imagine it would be that different.
OK, it’s third and two (see Fig. 1) and the offense is on its own 32-yard line (the blue line), so it needs to get the ball to the 34-yard line (the red line).  The markers (orange) are at the 24 and 34-yard lines and the yard marker (red oval) is at the 30-yard line.  (Remember that the down marker, which is not depicted, has a changeable board to indicate the current down and is positioned at the line of scrimmage.)  The quarterback hands the ball to the running back, who runs straight ahead.  He gets past the line of scrimmage, but two of the linebackers close in and he hits them like a brick wall before they drive him back.  The line judge, who is watching the running back from the sideline opposite the chains, runs in on the line where the running back gained forward progress before being driven back by the linebackers.  He looks up at the chains and sees that the ball is very close to the Line to Gain, the 34-yard line.  He lets the referee know it’s close.  The referee stops the game clock and calls for a measurement.
The umpire stands at the ball, on the yard line where the running back gained forward progress.  Meanwhile, the line judge walks onto the field, along the yard line where the yard marker has been placed and centers his foot on that line (see Fig. 2).  At this point, the head linesman goes to the yard marker and picks it up.  Along with the rest of the chain crew, he jogs out to the line judge and sets the yard marker down at the line judge’s toe.  The umpire takes the marker at his end of the chain and stretches it tight along the side of the ball, then stands the marker on the ground.  The referee then examines the marker and the ball to determine whether the nose of the football extends to the marker. 
If there is no chain visible between the nose of the football and the marker, the offense has a first down and the head linesman returns to the sideline with the chain crew and sets the chains at the new line of scrimmage and line to gain.  If, however, there is even a fraction of a chain link visible between the football and the marker, it is fourth down.  In that case, the head linesman picks the yard marker back up while the referee grabs the chain with his thumb and forefinger at the point where the nose of the football lines up with the chain.  The referee and head linesman, with the chain crew, return the chains to the sideline.  The head linesman then places the yard marker down exactly where it had been before the measurement (here, the 30-yard line).  The down marker is placed where the referee is holding the chain and its board is changed to “4” to denote fourth down.

Figure 1

Figure 2

Easy peasy, right?

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