Actually, that's not true. Out of 165 top 15 ranked fighters in the UFC (not including champions), 85 are American born (not counting American citizens that were born elsewhere). That's slightly above 50%, so yes, the majority of the UFC's top ranked athletes ARE American. And again, that's not including champions (most are American) or American citizens who were born elsewhere, like Uzman. Look at the p4p rankings - Americans hold the top 2 spots, 4 out of the top 5 spots, 9 out of the top 15. No matter how you dice it, Americans make up a disproportionate amount of UFC champions and top ranked contenders. If you're not American and you're a champion or in the top 15, it's likely you live and train in America. USA is the undisputed king of MMA.