Football Terms – Nickel Defenses
A nickel back is an extra defensive back used by the defense in certain passing situations. The player is known as a nickel back because he is the fifth defensive back on the field. Most football defenses have only four defensive backs in their standard alignment.
The nickel back typically is brought into the game when the offense is using a third wide receiver. This nickel back is usually the team’s 3rd or back-up cornerback. This player will go into the slot — inside the outer wide receivers — to cover the third receiver.
For matchup purposes, a defense will sometimes move their starting cornerback into the slot to cover the slot receiver, and slide their nickel back outside to cover one of the other flankers. When a nickel back is on the field, a team is said to be using their "nickel defense".
If a sixth defensive back is used on a play, this player is called a dime back and the defensive alignment is called a dime defense. If a seventh defensive back is used, this is generally called a prevent defense. This means that 4 (or less) defenders will rush the passer, while 7 (or sometimes even defensive backs will try to flood the quarterback’s passing lanes.
Any of these defensive schemes are supposed to make it much harder to pass against the defense, though it makes it easier to run against the defense.
Nickel Defenses and When They Are Moved
The nickel defense typically is used in long passing situations, or at the end of games when the defense is seeking to avoid long pass completions or quick touchdowns. In either situation, the defense will happily trade a few yards rushing in exchange for time running off the clock or the offense spending a down without getting a first down.