I personally don't like opening so many boxes at once, and I wouldn't recommend you guys do it either. Even though each box is random, I do see a trend happening at times where I get LFTs and MSs more often (sometimes 2 or 3 boxes apart). I usually open two boxes at a time. If I do get one of the big 3 items, I reset the count. If I don't, I stop and try again in a few hours. It seems to work for me at least. I dont feel as frustrated because even if I don't get the items I want, I'm preserving my boxes for when a streak comes along.