But the defense can cross BEFORE Three as soon as the QB pitches or hands - off the ball to another player .
The defense must wait for a count of THREE before they can cross the line of scrimmage to flag the QB .
The defense can cross BEFORE Three as soon as the QB pitches or hands - off the ball to another player .
The defense must wait for a count of THREE before they can cross the line of scrimmage to flag the QB .