Keeping the football off the ground is key for an offense in American Football.
There are a number of ways in which the ball can hit the turf, some are more costly than others.
In the majority of cases, if a pass is thrown to a receiver, not caught and the ball hits the grass then it is not a big deal.
However if a team on offense fumbles the ball that can have much bigger consequences.
What is a fumble?
Any player in possession of the football can fumble it, whether a quarterback on offense or cornerback on defense.
A fumble occurs when a player who had possession of the ball loses control of it before the play is over, either by going out of bounds, scoring or being downed.
A receiver is not considered in possession of the ball until they have made an “act common to the game” - which can include tucking the ball away, extending it, turning upfield or taking additional steps.
Once in possession, if the ball is dislodged in any way and no longer in possession of the receiving player then that is classed as a fumble.
For quarterbacks attempting a pass, if the ball comes loose before the throwing arm makes a forward motion then that is also classed as a fumble.
Once the throwing arm is moving forward in the motion of a pass then should the ball be dislodged and hit the turf it is deemed an incomplete pass.
How does a fumble differ from an incomplete pass?
The key difference between an incomplete pass and a fumble is that the defense can win possession of the ball if fumbled.
If a ball is fumbled, whichever team can reacquire it first will have control of the ball.
If they are not tackled or go out of bounds then play will remain live and the new player in possession can advance with the ball.
This often leads to mass pile ups on the ground with players from both teams fighting at the bottom for possession.
If a pass is incomplete the play is over and players will return to the previous line of scrimmage.
Can anyone advance a fumbled ball?
For the most part, yes. But not all the time.
In the final two minutes of each half of an NFL game, if a player on offense fumbles the ball they are the only player on the team who is allowed to advance with the ball should it be reacquired.
If another player on the offense gathers the fumbled ball the play is ruled dead at the spot of the fumble.