It's just a nickname for the area between the 20 yard line and goal-line where an offense has a good chance at scoring. You could also say its a warning for opposing defenses to make a stop during the opposing team's drive. It's basically a nickname that came into being as a warning to the defense who is "in the red".
It is on the offensive side of the ball, across the line of scrimmage. It is called off sides or neutral zone infraction.
the line dividing the zone of accumulation from the zone of ablation on a valley glacier is called the?
Inside Line Backer
The first end zone line, ususally referred to as the goal line.
The length of the football defines the width of the neutral zone. When the referee places the ball on the ground, no player on either team (except the center on offense) may may line up with any part of their body inside the neutral zone. The neutral zone extends the entire width of the playing field.
when the ball is on the oppenents 20 yard line-oppentents goal line
The 20 yard line is considered the beginning of the Red Zone
It is the imaginary area between the defense's 20-yard line and its goal line from which the offense is most likely to score points. It also is how well a team performs in the red zone can often determine the outcome of a game.
from the 20 yard line to the back of the touch down
the phase "red zone"came from if the offense couldn't get the ball in the end zone from the opponents 20 yard line then it was embarrassing and their faces turned red. That's how the term "red zone"came about in football.
That line is called the line of scrimmage.
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