The card stock affects not just how your cards look, but how they feel, how long they last, and how they perform during repeated use
Very rare and severe misprint errors can also be very valuable, like cards that are missing attack values or cards that are printed with a Magic: The Gathering back
Its unclear how long any of these experiments will last, but all indications are that this is the way going forward
When an MTG Battle card is played, its controller chooses a player to be its protector (there are restrictions on this depending on the Battle type)
You know you're going to kill it with either Bile Blight or Ultimate Price, but you need to decide which one to use
This test can be brought to a very sophisticate level using an external flash connected to a camera in an artisanal black box