The Wall Street Journal, of all places, explains a devastating running play by the New York Giants called the counter.
Simply put, on a snap, a lineman fakes out its assignment, cuts back, run around the other linemen, and takes out either a linebacker or safety. Meanwhile, one of the running backs follow the “countering” lineman and goes toward the end zone.
As a result, even if defenses knew it was coming, there are many ways a “counter” can be executed, and they still have to contend with an extra blocker and having to take down Brandon Jacobs.
I’ve wondered why, despite the lack of an elite back, the Giants having the best running game in the league. This sums it up perfectly.