InAmerican football, anickelback, also referred to as aslot cornerback orslot corner,[1] is acornerback orsafety who serves as the additionaldefensive back in anickel defense. A base defense consists of two cornerbacks and two safeties, making the nickelback the fifth defensive back on the field, thus tying the name of the position to the name of the North American5-cent piece.
The nickelback is the thirdcornerback orsafety on thedepth chart. Usually, the nickelback will take the place of alinebacker, so if the team had been in a4–3 formation, the fourdefensive linemen would remain, alongside only two linebackers and now-five defensive backs, creating a4-2-5 formation. However, some teams will replace a lineman rather than a linebacker, creating a three-linemen, three-linebacker and five-defensive back alignment, a3–3–5 formation.
If an offensive team always uses three or morewide receivers, a defense may turn to a nickel defense for their base package on most plays. Usually, extra defensive backs, such as a nickelback, are substituted into the defense in situations where the opposing offense is likely to attempt aforward pass, such as 3rd-and-long, or when extra receivers are substituted into the opposing offense. In other cases, the nickelback must also be able to tackle in the open field in run situations, and as such, the position can be considered a hybrid run/pass defender,[2] and in some cases, such asblitzes, even a pass rusher from outside the box.
The nickelback is generally not considered a starting position because the starting formations for most defenses are either a 3-4 or a 4–3, in which only two cornerbacks and two safeties are utilized. Defensive formations with three or more cornerbacks (or three safeties) are used often enough that a nickelback will usually see moderate playing time—particularly in the modern, pass-orientedNational Football League (NFL)—as well as substituting in for the starting cornerbacks. Some teams, such as theSean McDermott-coachedBuffalo Bills, use a base nickel defense, with slot cornerTaron Johnson serving as a consistent starter on the Bills due to this philosophy.[3] Other notable defensive backs known for playing primarily in the slot includeTrent McDuffie,Kyle Hamilton,[4]Elijah Molden,Michael Carter II and more recently,Cooper Dejean.[2][5]
InCanadian football or theCanadian Football League (CFL), where five defensive backs are considered the norm, the position is known as adefensive halfback.