Defense

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Defensive Line

The defensive linemen plays an important role in pressuring the quarterback and stopping the run. This positions consists of defensive ends and tackles. If they are strong enough, they can overpower the offensive line and sack the quarterback or prevent them from having enough time to find open receivers. They also help tackle the running back for a short gain or stop them from crossing the goaline. If they're lucky enough, they can swat passes or even catch an interception from tipped footballs.

Linebackers

Linebackers are positioned above the linemen and just like a defensive lineman, They are known to stop the run, sack the quarterback, but also prevent short or medium passes from being completed. However, they are not built to defend long passes from faster receivers, since they'll be completely overwhelmed. Some linebackers can be athletic enough to snag an interception from the air.

Defensive Backs (Cornerbacks and Safeties)

Also known as the secondary, which consists of cornerbacks and safeties, defensive backs plays an important part for defending every pass thrown by the quarterback. They can lockdown receivers or tight ends, which prevents the quarterback from having any option to pass to an open receiver. They can also leave coverage and even assist in sacking the quarterback, although, that might leave more open receivers, which is a hugh risk to take. The cornerbacks guards and stays with the receivers, while the safeties protects the deep passes for a long gain or in the endzone.