Football is littered with specialized terminology. From 4-3 under front to deep comeback route, commentators rarely get to explain everything you need to know before the next play. Inside The Pylon’s glossary was developed to give fans a deeper understanding of the game through clear explanations, as well as image and video examples. Please contact us with any terms or phrases you’d like to know more about.

Line of Scrimmage

The line of scrimmage, abbreviated LOS, is an invisible horizontal line, across the width of the field and perpendicular to the sidelines, at which the front nose of the football is placed by officials when spotting it prior to the next offensive play. The offense must line up at least seven players on the LOS (or, more accurately, just behind it, because of the neutral zone), while no defensive players are required to do so.

Before the snap, the TV broadcast will usually mark the line of scrimmage with a solid, neutral colored line ‒ usually blue ‒ while marking the first down with an orange or yellow line and the “FG target line” with a bright red:

In this close up, New England Patriots wide receivers Danny Amendola ‒  in the slot, off the line of scrimmage ‒ and Brandon LaFell – on the line of scrimmage ‒ prepare to execute a play against the New York Giants defensive backs Trevin Wade (#31) – in the slot, on the line of scrimmage ‒ and Trumaine McBride (#38) – outside on LaFell, and off the line of scrimmage.

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Mark Schofield contributed to this entry. Follow Mark on Twitter @MarkSchofield.

All video and images courtesy NFL Game Pass.