A swing pass pattern in Football is a receiving route that is usually reserved for running backs in which the receiver runs parallel to the line of scrimmage towards the sidelines while remaining behind the line of scrimmage. This pass route is most often used as a checkdown, or 'dump off,' option for the quarterback if no other receivers are open and the quarterback is under pressure from the defense.
Very rarely are receivers who run the swing pass pattern the primary receiver, or the receiver who is the go to target, and this route is usually reserved for running backs in the backfield or tight ends at the end of the line of scrimmage who are not blocking.
There is quite a bit of risk surrounding the swing pass pattern as it is one of the most prevalent routes in football, thus the easiest to read from a defensive standpoint. Because the player running the swing pass pattern must run parallel and slightly backwards from the line of scrimmage before moving forward, that gives opposing defensive backs and linebackers plenty of time to read the play and intercept the pass if it were to go to that receiver. Any interception where the intended target was a receiver running a swing pattern is very likely to become a pick-six as the only line of defense left is the quarterback, who is often not very fast.