At this age level, the teams that can stop the Sweep/Counter/Reverse will have the most success. Some concepts I use, we play a 2-3 Zone. I am a firm believer that zone is the way to go until passing becomes more prevalent. Playing zone allows you to defender the sweep/counter. When I'm calling "O" I love to see them in M2M as the Counter/PA game really open up. The "2" are called Defensive Ends, the align 2/3 yards deep and 3/4 yards wide of the Center. I repeatably tell them their only job is containment. The target point on the BC (Ball Carrier) coming toward them is the outside hip...in fact if they make a flag pull on the inside hip I get on them. If the ball is flowing away from them they are to think counter/reverse and not pursue the ball until it crosses the LOS. The MLB in the "3" is free to flow aggressively to the ball. The OLB in the "3" have secondary support on outside containment when the ball is flowing toward them. If DE contains we then have the BC cutting back inside the DE with MLB and Playside OLB filling in, it gets very crowded in there. The OLB in the "3" when the ball is flowing away from them looks for Counter/Reverse. Once he determines not Counter/Reverse then he is instructed to but a "Cap on the Run" pursue hard at a 45 degree angle and get behind the MLB and playside OLB and in front of the BC. You basically hear 3 things out of me during the game. 1.) DE's "Outside Hip" 2.) LB "No one gets behind you for a pass". 3.) Trust your teammates, do your job, stay in the zone.