But, the basic spot for fouls during a running play is the end of the run. This run, with consideration of momemtum, ends at the 4 YL. In order to enforce it from the goal line, the momentum exception should not be in consideration. If the run ends in the end zone, ie. the player forces the ball across the goal line without momentum, then it would be enforced from the goal line. For example, if he got the ball at the 6 YL and ran into the end zone, then enforcement would be at the goal line.