A lot of testing new cards involves playing with them, so playtesting itself involves a lot of math just in the gameplay alone
If, during a player's declare attackers step, a creature that player controls that's been goaded is tapped, is affected by a spell or ability that says it can't attack, or hasn't been under that player's control continuously since the turn began (and doesn't have haste), then it doesn't attack
Red Cheeks Pikachu only appeared in the Shadowless and 1st Editions of Base Set (and one e3 promo card)
But why are these colorful cards becoming such a hot target
Lets search for a commander who cares about noncombat damage, for example: This can be extremely useful if youd like to do something super specific with your deck, but bear in mind that you should try variations on your theme
Grading is an evaluation of a card's condition on a scale of 1 to 10, with higher grades indicating cards that are near-mint or mint