In 2012, ESPN became a broadcast partner with the NCAA. As such, we are bound by the NCAA rules, and two main clauses which state

A) No cash prizes can be awarded.
B) The contest winner must incorporate a random drawing element for any prizes. We chose to do the random drawing from the top 1%, while the other major broadcast partner's game uses the top 10%.

Due to this ESPN utilizes random drawing when selecting the winner of the Grand Prize. 

Good luck with your picks!