If you would guess a card, instead just choose the outcome you want. At the beginning of each opponent's upkeep, look at the top card of their library. Tell them the name of that card. They tell you its mana cost, type line, power, and toughness. Then reveal that card. If they got anything wrong, draw a card.
Near Mint - $41.75
Lightly Played - $39.75
Moderately Played - $33.50
Heavily Played - $25.25
Damaged - $21.00
Near Mint Non-English - $41.75
Lightly Played Non-English - $39.75
Moderately Played Non-English - $33.50
Heavily Played Non-English - $25.25
Damaged Non-English - $21.00