A curl pass pattern, also known as a curl route, is a route run by a receiver. In short, the receiver, starting from the line of scrimmage, runs anywhere from around 12 to 15 yards downfield, though this range can vary slightly. At this point, the receiver turns back to the quarterback in the direction of the ball at about a 45-degree angle and comes back to the pass with a few steps.
This is in contrast to a comeback route, in which the receiver runs the same distance and cuts at the same angle, but does so toward the sideline, away from the quarterback. Other similar pass patterns include the hook and hitch routes. A curl route can be considered a type of hook route and is very much like a hitch route. However, a receiver running a hitch route runs a shorter distance before cutting back.
When done correctly, a curl route is difficult to defend, and will often be used as a relatively safe way to pick up yards when it comes to pass plays. A curl route can be used to gain separation from a defender but can also target an open area in a zone defense. Because the route includes a quick, slightly rounded turn back to the passer, the plant foot, and footwork in general, is incredibly important.