the platinum cup that u see in gang battle are calculated from the other trophies u get ... lets just give an example .. 2 gold trophie makes 1 platinum or 5 bronze makes a gold ... i dont know the exact ratio but at least u got an idea.
edition: ive read that u can also get a platinum trophie from the soccer league...the above still apply to the gang trophie u can see tho.
