An official shall declare the ball dead and the down ended:
Item 1. Contact by Team B Player. If a Team B player contacts the passer or the ball after forward movement begins, a forward pass is ruled, regardless of where the ball strikes the ground or a player. When this occurs, intentional grounding rules do not apply.
If a Team B player contacts the passer or the ball before forward movement begins, the direction of the pass is the responsibility of the passer, and grounding rules apply.
Item 2. Passer Tucks Ball. If the player loses possession of the ball during an attempt to bring it back toward his body, or if the player loses possession after he has tucked the ball into his body, it is a fumble.
Item 3. Passer re-cocks his arm. If the player loses possession of the ball while attempting to re-cock his arm, it is a fumble.
Item 4. Fumbled or Muffed Ball Goes Forward. The fact that a fumbled or muffed ball goes forward is disregarded, unless the act is ruled intentional. If it is intentional, a fumbled ball that goes forward is a forward pass (8-1-1), and a muff is a bat (12-5-1).
A player is in possession when he is inbounds and has control of the ball with his hands or arms.
To gain possession of a loose ball that has been caught, intercepted, or recovered, a player (a) must have complete control of the ball with his hands or arms and (b) have both feet or any other part of his body, other than his hands, completely on the ground inbounds, and, after (a) and (b) have been fulfilled, perform any act common to the game (e.g., tuck the ball away, extend it forward, take an additional step, turn upfield, or avoid or ward off an opponent). It is not necessary that he commit such an act, provided that he maintains control of the ball long enough to do so. This rule applies in the field of play, at the sideline, and in the end zone.