They also don't use pure randomness. They very finely tune the way the drops come out. If there's a card you don't have (or that you don't have much of), there'

They also don't use pure randomness. They very finely tune the way the drops come out. If there's a card you don't have (or that you don't have much of), there's a MUCH higher chance of finding it than a card you've maxed out, or that is at similar level to the rest of your cards.