A Man-in-Motion is playing on the offensive football unit who moves prior to the snap laterally along the line of scrimmage from one position on the field to another. Typically, running backs, tight ends and wide receivers are the offensive players who go in motion. This player must come to a rest and be facing the defensive side of the ball — called "being set" — before the snap of the ball.
The man-in-motion has several purposes in football. Deception is a major reason for motion. Because defenses read an offense’s alignment and sometimes makes adjustments or audibles, motion gives the defense a different look just prior to the snap of the ball, hopefully too late for the defense to make new changes. The original offensive alignment was an attempt to trick the defense into calling one defensive assignment, which will hopefully cause confusion when a different sort of play is called from the new alignment.
Motion Mismatches – Football Schemes
Man-in-motion also attempts to create mismatches. For instance, if an offense notices that a slow linebacker is the playing following a quicker running back into the slot, then the offense might send the back in motion to create this match-up situation.
Also, sending a man in motion is a way to eliminate extra tacklers from a run situation. For instance, if you intend on running a dive or a draw play, you might send one of your running backs in motion. This will cause a defender to follow the running back out to the wing of the defense. Instead of calling on your fullback to block a linebacker, you might simply have the fullback draw the linebacker out into coverage, where he is effectively out of the running play. This requires judgment, as to whether that is a better match-up than having an extra blocker in the play.
Tight End in Motion
Sending a tight end in motion helps to bring an extra blocker into a running situation at the point of attack, without betraying early on where the run is going to focus. For example, you might line your tight end up on the right side of the line, then send him in motion left. As the tight end reaches the point of attack, he will set and ready to block at that point along the line. This entails bringing an extra defensive player to the point of attack, but this sometimes makes sense in short yardage situations.
Often, tight ends will go in motion in short yardage situations where there are multiple tight ends on the field. In a goal line situation there are often two or three tight ends on the field, and an extra blocking tight end might go in motion to change the direction of the run (or how the defense perceives where the run will be) at the last moment.
Also, a tight end might go in motion, but release from the blocking scheme at the last moment, giving him a chance to get open for a short play-action pass.
Slot Receivers in Motion
Wide receivers are used as a man in motion to create new match-ups and mismatches. Often, an offense will place its best receiver in the slot, then send him in motion to the other side of the field. The defense is likely to have set up an extra safety to help in double coverage against the star receiver, but the defensive alignment might not allow for the same on the other side of the defense. Therefore, sending a receiver in motion might free him from double-coverage into a single-coverage situation.
Joe Gibbs – Motion Scheme
In the past 25 years, motion offenses have become much more standard in the National Football League. Joe Gibbs, an offensive coordinator with the San Diego Chargers and (more famously) the three-time Super Bowl winning head coach with the Washington Redskins, is generally given credit for introducing a greater degree of motion into the NFL.
The Washington Redskins of the 1980′s had trouble blocking Lawrence Taylor of the New York Giants, who was a new kind of pass rushing outside linebacker. Taylor often required double teams in the blocking scheme, but this could become too predictable if it was from the same alignment every play.
Gibbs devised a motion offense where multiple players would go in motion prior to the snap, disguising the Redskins intentions and setting up multiple opportunities to block LT from different angles.
H-Back – Man-in-Motion
Joe Gibbs also invented the H-back position, which is a hybrid of a tight end and a fullback. The H-Back catches more passes than the standard fullback and is closer in size to the traditional tight end, but still often performs the blocking functions of a fullback. This meant that Gibbs got an extra player on the field large enough to block Lawrence Taylor, but trained to go in motion enough that he could attack the defense from several positions along the line of scrimmage.
The H-back would act as a man-in-motion more often than either a tight end or a fullback, and would often be used to either "chip" or double-team LT. Because the H-Back was designed to be a pass catcher, he might be sent into a pattern to either draw Lawrence Taylor from his pass-rushing duties or, once again, block LT and then run a short route — called chipping because it’s not a full stay-in-the-pocket block.
Since that 1980′s, most NFL offenses use the man-in-motion from time to time, either for deceptive or mismatch purposes.