Quarterback sack

[1] This often occurs if the opposing team's defensive line, linebackers or defensive backs are able to apply pass pressure (also called a pass rush) to quickly get past blocking players of the offensive team (the quarterback's protection), or if the quarterback is unable to find a back to hand the ball off to or an available eligible receiver (including wide receivers, running backs and tight ends) to catch the ball, allowing the defense a longer opportunity to tackle the quarterback.

Performing a sack is advantageous for the defending team as the offense loses a down, and the line of scrimmage retreats several yards.

Unique situations where a loss reduces a quarterback's rushing total (not a sack) are "kneel downs" (used to run time off the game clock).

"[6] According to former NFL coach Marv Levy, Washington Redskins coach George Allen may have coined the term when referring to Dallas Cowboys quarterback Craig Morton[7] when he purportedly stated before a game, "Before we play those Dallas Cowboys, we’re going to take that Morton salt and pour him into a sack."

[10] Controversial NFL rule changes made for the 2018 season prohibit tacklers from landing on the quarterback after making a sack, with the punishment being a roughing the passer penalty.

[11] Of all forms of defensive pressure against the opposition's passer, sacks provide the most immediate impact by ending the offensive play.