I run a loose grading scale, based on my personal interest in the card:
Slam it - The holy-crap-I-am-so-happy-they-printed-this card.
Cube - This card will go into my cube and I expect to be happy with it.
Needs testing - The card looks like it could be powerful, but may or may not work out.
Playable - Interchangeable with similar cards, depending on the flavor of the moment might see play.
So close - I want to play this, but it's probably better if I don't.
? - No idea what to think of this card.
Pass - Not interested. Every card not listed here automatically gets this grade.
If the card is not on this list, you can assume I'm not interested, is a reprint (or forgot to list it). Some reprints will get listed if it's the first time it gets a modern border.
Link to Modern Horizons card image gallery on Dailymtg.com
