There are certain schools that get top shelf recruits while others fight over the table scraps, and the pre season rankings reflect this.
The table scraps often play with a chip on their shoulder though, in an effort to prove that they're not table scraps.
The top shelf recruits, conversely, are only thinking about the NFL for the most part.
So often times the teams full of table scraps will beat the teams full of top shelf recruits.
That's one of the many dynamics that make it all so wildly entertaining.