If you've been out to the Jacksonville Jaguars training camp practices, you might have noticed two lines running down the length of the field. There is a red line between the numbers on the field and the hash marks, parallel to the boundary line the length of the field.
So what is that for?
We don't know exactly what they are for, but based on something that the Seattle Seahawks also do with Pete Carroll, I think we have an idea.
The Redline on Offense
Last season Seahawks players constantly talked about "controlling the redline" in the passing game. It appears to be a central focus both offensively and defensively in setting up plays and coverages.
The concept was essentially that the receivers tried to control their width to the sideline rather than trying to blow past defensive backs. If a receiver was able to "control the redline" on his deep route, he would leave the quarterback ample room to lead the receiver to catching the football over the top, even if it led him out of bounds.
What this did, if the receiver controlled the line, was give the quarterback a cushion to drop the ball in so the receiver could tail off and catch the football, all the while controlling how close to the sideline he actually would be. It gives the quarterback a known margin of error and landing point for his throw which should in turn make it easier for the receiver to make a play on the ball.
From Field Gulls:
It seems when the ball is traveling a long distance, Seattle wideouts end the play with the catch - Sidney Rice, in particular, has very little YAC; he is usually tumbling to the turf making an amazing toe drag and using his catch radius while diving for a pass. If you close your eyes and think about the big catches in 2012, think about how many of them ended with the receiver falling to the ground, into the end zone, or near the sideline.
Essentially it opens up the quarterback to be able to make those "bucket throws", which drop in the outside shoulder (sideline shoulder) of the receiver and over the top of the corner. A lot of times corners will play the receiver with the boundary, trying to give them little room to work with, which is why the Seahawks receivers tried to control that redline and give themselves some space. It also allows for the quarterback some leeway in that if he misses on the pass, he should miss long and put it where only the receiver can make a play.
The Redline on Defense
On the defensive side of the ball one of the things Carroll liked to control was the deep middle of the field, which we now know is why he rated Early Thomas so highly. Thomas plays as a single high safety a lot of the time for the Seahawks and completely owns the area between the numbers.
Ideally, the safety in this defensive scheme should be able to break on a ball thrown 20+ yards down the field in either direction (or, to the redlines) and the corners will in turn like the receivers attempt to control that redline, knowing they have help with the safety over the top. It would also explain why length and the jam is something that seems to be so important for defenders in the secondary, as it will help control that redline and buffer area on to the boundary.
Now, as I've said we don't know for sure that is what these are for, but based on what Seahawks players said and did last season, it seems this is likely the case.