Board Thread:News and Announcements/@comment-26581304-20150906194347/@comment-24577221-20150911204313

So far as I know, X + Y can give you Rare XY regardless of whether X and/or Y are Rares themselves, and I don't know of any information suggesting that the chance of getting Rare XY is affected by whether or not X and/or Y are Rares. It's a kind of thing that's hard to get data on, since the time available for collecting information is short and unpredictable.