I hate when games hold tournaments for say, the top 1000 on the leader boards. The leader boards mean nothing other than the ones at the top obviously have a lot more free time on their hands than me. Like in CoD4, I was never a gold cross prestige, but I made my way easily to 8th prestige, and played against countless people in the top 1000 and was just as good if not better on certain maps or with certain weapons.
I don't know how this tournament was determined, but I bet it was an on location type of thing.