The best way to stop the run game is using either the 3-4 defense. One of the best blitzs to use is the weak side blitz. This is when you have your linebackers on the opposite side of the tight end blitzing. The next thing that you do is spread the linemen out using the linemen shift, and shifting the linebackers toward the tight end using the linebacker shift. The next thing to do is to bump and run those widereceivers, giving more time for your blitzing linebackers to either stop the run, or reach the quarterback. This play, "SHUTS THEM DOWN", especially when you are the safety and you are back there creating more run/pass support.

Another, more difficult way to stop the run is to confuse the offensive lineman into thinking that you are going to rush using the safety. Pick the safety, and bring him down to the line. Move him around, make the offensive lineman think that you are about to rush. When the ball is hiked, fake like you are going in for the kill, and move either back to pass defense, or move toward the running back. The lineman will be confused, and that frees up your linebackers, and your lineman to rush the runningback/quarterback. The key here is to make atleast one of the lineman commit towards you, distracting them from the linebackers blitzing.

Remember to shift your linebackers and your lineman around when you are blitzing. Following the actuall play will never get you to the super bowl and an undefeated season. And every once in a while, the runningback will get free. Someone like ricky williams, or michael bennet is just too hard and too fast to catch and bring down. That is why you as the safety must know how to get in there and disrupt the play, or in rare cases, make open field tackles.