Using the pass, not the run

Fair notice: I'm not very knowledgeable about football play calling. I know that there are runs and there are passes and I bet that throwing on 3rd and long is a good idea and running on 3rd and short is a good idea... that's about it. That being said, this article piqued my interest (even though I've only read the abstract) since the writers attempt to cull some conclusions from a load of play calling data.