http://forums.spiralknights.com/en/node/2283#comment-14940
My bad, that system wouldn't work either. I realize the problem is that in a system that dictates who gets what based on both the order specified by the current Round the Robbin sequence and when the item is picked up, players who have already received an item can exploit it by collecting poor quality items until the next Round the Robbin Sequence begins giving them a chance to get the good item. Such exploitation is only possible when more items then the current Round the Robbin sequence logic is able to dictate are present.
A solution is to change it from "a system that dictates who gets what based on both the order specified by the current Round the Robbin sequence and when the item is picked up" to "a system that dictates who gets what based on both the order specified by the current Round the Robbin sequence and when the item is dropped".
If the logic is applied when the items are dropped rather then when they are picked up, players can't exploit or game it. This allows the original proposal of a randomized Round the Robbin sequence to function perfectly. A player who has already received an item, can no longer collect inferior items to have a chance at a good quality item as all items are already distributed, just waiting to be picked up.
Because that would require them lowering the drop rate as a whole and would completely demolish the Trade aspect of the game.