Prevent defense
Encyclopedia
Prevent defense is an American football
American football
American football is a sport played between two teams of eleven with the objective of scoring points by advancing the ball into the opposing team's end zone. Known in the United States simply as football, it may also be referred to informally as gridiron football. The ball can be advanced by...

 defensive alignment that uses seven or more defensive back
Defensive back
In American football and Canadian football, defensive backs are the players on the defensive team who take positions somewhat back from the line of scrimmage; they are distinguished from the defensive line players and linebackers, who take positions directly behind or close to the line of...

s or players in a defensive back role, the goal of which is to prevent the opposing offense from completing a long pass. This defense is frequently used in obvious passing situations, such as a third-and-very-long situation, or to prevent a long score on the last play of a half, or when the defense believes that the offense must pass (for example, if the offense is trailing late in a game). Otherwise the prevent is almost never used. The defense trades size for speed, and tries to ensure that no receiver
Wide receiver
A wide receiver is an offensive position in American and Canadian football, and is the key player in most of the passing plays. Only players in the backfield or the ends on the line are eligible to catch a forward pass. The two players who begin play at the ends of the offensive line are eligible...

 can get behind the defense. A prevent defense backs up the coverage so far that it will often give up long yardage, but it makes scoring a touchdown
Touchdown
A touchdown is a means of scoring in American and Canadian football. Whether running, passing, returning a kickoff or punt, or recovering a turnover, a team scores a touchdown by advancing the ball into the opponent's end zone.-Description:...

 in a single play very difficult.

Quarter defense

The quarter defense has 3 down linemen, 1 linebacker
Linebacker
A linebacker is a position in American football that was invented by football coach Fielding H. Yost of the University of Michigan. Linebackers are members of the defensive team, and line up approximately three to five yards behind the line of scrimmage, behind the defensive linemen...

, and 7 defensive backs. The quarter defense gets its name as the next coin after nickel
Nickel defense
In American football, a nickel defense is a defensive alignment that uses five defensive backs, of whom the fifth is known as a nickelback. Although the modern definition of the term encompasses all formations featuring five defensive backs, the original and still most common form of the nickel...

 and dime
Dime defense
In American football, the dime defense is a defensive alignment that uses six defensive backs. It is usually employed in obvious passing situations....

 in the sequence of defenses. Quarter or quarters can also be used to describe a type of zone pass coverage
Zone defense
Zone defense is a type of defense, used in team sports, which is the alternative to man-to-man defense; instead of each player guarding a corresponding player on the other team, each defensive player is given an area known as a "zone" to cover....

, in which 4 defensive backs divide the field into vertical quarters for zone coverage. This coverage may be combined with a 4-3
4-3 defense
In American football, a 4–3 defense is a defensive alignment consisting of four down linemen and three linebackers. It is probably the most commonly used defense in modern American football and especially in the National Football League. NFL teams that use the 4–3 defense as of 2011 include the...

 or 3-4
3-4 defense
In American football, the 3–4 defense is a defensive alignment consisting of three down linemen and four linebackers.The 3–4 defense declined in popularity over the years, but has found renewed use by modern professional and college football teams. The 3–4 defense is so named because it involves 3...

, and is used to take away deep routes but maintain a good pass rush and run coverage.

Half dollar defense

Half dollar defenses have 8 defensive backs and are very rare and are often used to prevent a Hail Mary pass
Hail Mary pass
A Hail Mary pass or Hail Mary route in American football refers to any very long forward pass made in desperation with only a small chance of success, especially at or near the end of a half....

. Professional teams may not have enough defensive backs on the roster to play the quarter or half dollar, so wide receivers are sometimes used to fill the extra positions, particularly in late game situations where the receiver's offensive skills can be put to good defensive use.

Implementation

In this case the defense will pull back into what is called a soft zone. They will most likely play in a nickel, dime, or quarter package. A soft zone means that all the safeties and cornerbacks are playing back, five or ten yards off the line of scrimmage. The free safety will often play as much as 20 yards back. There will be no jamming of receivers on the line. The zone means that each defensive back is responsible for an area of the field, so they're all watching the quarterback's eyes instead of running stride for stride with a receiver. It is very easy for the offense to make short plays against this defense, gaining four to eight yards per play, but it's almost impossible for the offense to make a big play of 20 or more yards against this sort of defense.

Advantages

In the fourth quarter when there are only a few minutes left in the game and one team is winning by 7 or more points, it's common in the NFL for that team to go into a "prevent" defense. In a prevent defense the idea is to make the other team use up a lot of time. The clock is stopped when the player with the ball steps out of bounds, so the first goal of the defense is to keep everyone in bounds. The only danger to the defense is giving up a big play, for example a 25 yard or longer pass or run. It doesn't matter to the defense if the other team makes a lot of plays, and gains four to eight yards per play, as long as the clock keeps running.

Examples

In Super Bowl XXXII
Super Bowl XXXII
Super Bowl XXXII was an American football game played on January 25, 1998 at Qualcomm Stadium in San Diego, California to decide the National Football League champion following the 1997 regular season...

, Denver Broncos coach Mike Shanahan
Mike Shanahan
Michael Edward "Mike" Shanahan is the 28th and current head coach of the Washington Redskins of the National Football League. Shanahan also holds the title of Vice President of Football Operations with the Redskins, giving him full control over player personnel with the team. Shanahan previously...

 famously instructed his defensive coordinators to keep playing the same defense as the Green Bay Packers attempted to drive downfield in the final two minutes of the game. The Denver defense managed to stop the Packers' drive, which led to the Broncos' 31-24 victory.

Disadvantages

The prevent defense is rarely used on consecutive downs, or with a significant amount of time remaining, since a team with time to move downfield would easily be able to gain plenty of intermediate yardage. John Madden
John Madden (American football)
John Earl Madden is a former American professional football player in the National Football League, a former Super Bowl-winning head coach with the Oakland Raiders in the American Football League and later the NFL, and a former color commentator for NFL telecasts. In 2006, he was inducted into...

once said, "All a prevent defense does is prevent you from winning."

The bend-but-not-break nature of the prevent defense tends to give the offensive team many easy gains but no big play, so the prevent defense can make the end of the game uninteresting for fans. Some coaches avoid using the prevent defense, choosing instead to continue playing the same defensive schemes that ostensibly gave them the lead to that point.
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