Intentional grounding

In gridiron football, intentional grounding is a violation of the rules where "a passer...throws a forward pass without a realistic chance of completion." This typically happens when a quarterback about to be sacked passes the ball toward an area of the field with no eligible receiver. Were it not for this rule, the quarterback could easily turn the sack into an incomplete pass which, by rule, would advance the ball back to the line of scrimmage.