Strength Call

A defense declares the strength of the offense so that it can get aligned and determine responsibilities. These are usually gap responsibilities for the linemen and linebackers and coverage responsibilities for the linebackers and defensive backs. There are several ways a defense might call out the offense's strength.

Line strength

The defense checks whether one side has a tight end attached.

Passing strength

The defense checks how the receivers are set.

Back strength

Are there more backs to one side of the formation?

Field strength

Where is the ball placed on the field? Is it on the left or right hash?

Talent

Is there a player on the offensive line the defense wants to take advantage of or avoid?

Many of the strength calls above can be balanced. In this case, the defense usually has a tiebreaker and a default. For example, it might call the strength based on the passing strength using the wide receivers, then use the back strength as a tiebreaker.

Motion can cause issues with strength calls based on passing strength when a receiver motions across the formation. One solution is to always set the strength to the field.