It's not illegal! There is no regulation requiring you to place the ball between your legs. You can't hold onto the ball and run forward instead of snapping it; you can't imitate a snap and not snap it; and you can't hold onto the ball and run forward instead of snapping it. This rule exists only because old photographs sometimes show players with the ball between their legs. There are two ways to legally snap the ball: a lateral swing, where you swing the arm across your body and snap the ball toward the opposite side of the field; or a forward swing, where you swing the arm straight back and snap the ball forward. The ball must be held in the hands until the moment of the snap. Once it's in the hands of the holder, they are free to do whatever they want with it. Most often, that means throwing it forward into the end zone. However, if they take too long to release it, another player may be allowed to take over by simply catching it out of their hands. There are times when it may appear that a player has snapped the ball between their legs, but this is not legal. For example, if a quarterback were to slide and roll away from the play while keeping control of the ball, he would be considered to still have the ball in his hand at the point of contact.