Slotback

In both Canadian and indoor football, slotbacks can make a running start toward the line of scrimmage before the snap.

When formations containing slotbacks are used in American football, the team often has to go without a tight end, a fullback, or a running back since there are only 11 players allowed on the offense and 7 of those are on the line of scrimmage.

Slotbacks are similar to wide receivers, with the exception that they line up closer to the quarterback and can use the waggle (motion before the snap).

They will block on the lesser-called run plays, as the tight end position is essentially obsolete in the CFL.

However, as NFL teams have increasingly "defaulted to three- and four-receiver sets" in recent years, the slot receiver has become a fixture of American football formations.