Shadowverse

How do you manage to get so many Leader cards from 70 packs? Teach me! In all my time playing, I've only gotten one Leader card, and it wasn't very good. However, I can't really complain – in the last few days, I've opened about ten more packs, and I got two animated Legendaries (the second being Tot and the Haven princess) + 1 non-animated one. It's funny, considering I only play the campaign.