Why is there a yardage penalty as well as loss of down imposed for intentional grounding, but not when the QB spikes the ball to stop the clock--he's still inside the tackles at this point. Is it because he is not doing it in anticipation of a sack? Beth

Spiking the ball to stop the clock is a legal play; intentional grounding is an illegal play. Loss of down and yardage penalty is the worst type of penalty, and yes, it is because the QB is attempting to avoid a sack.