Article 3. Completed or Intercepted Pass
A player who makes a catch may advance the ball. A forward pass is complete (by the offense) or intercepted (by the defense) if a player, who is inbounds:
Note: If a player has control of the ball, a slight movement of the ball will not be considered a loss of possession. He must lose control of the ball in order to rule that there has been a loss of possession.
- secures control of the ball in his hands or arms prior to the ball touching the ground; and
- touches the ground inbounds with both feet or with any part of his body other than his hands; and
- maintains control of the ball after (a) and (b) have been fulfilled, until he has the ball long enough to clearly become a runner. A player has the ball long enough to become a runner when, after his second foot is on the ground, he is capable of avoiding or warding off impending contact of an opponent, tucking the ball away, turning up field, or taking additional steps (see 3-2-7-Item 2).
If the player loses the ball while simultaneously touching both feet or any part of his body to the ground, it is not a catch.
Item 1. Player Going to the Ground. A player is considered to be going to the ground if he does not remain upright long enough to demonstrate that he is clearly a runner. If a player goes to the ground in the act of catching a pass (with or without contact by an opponent), he must maintain control of the ball until after his initial contact with the ground, whether in the field of play or the end zone. If he loses control of the ball, and the ball touches the ground before he regains control, the pass is incomplete. If he regains control prior to the ball touching the ground, the pass is complete.
this explains it pretty good, every football fan should know this by now
for most of the history of football, that was a catch, when I played as a kid, that was a catch
in the NFL in 2017 with instant replays and the rule being what it is, it's incomplete