LogFAQs > #966496471

This is a really minor optimization step but the game's algorithms are set up in a way where until you own 4x of every single rare and mythic, you will always get a rare or mythic that you don't own 4 of yet when you open packs. This means that if you're focusing on draft, you shouldn't open any packs from that set unless if you specifically need cards from that set. This reduces the chance of you opening rares or mythics that you'd be drafting anyways.