Most played cards in UR:

1 Decks
Mishra's Factory
4 copies - 4 average
Su-Chi
4 copies - 4 average
Serendib Efreet
4 copies - 4 average
Volcanic Island
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Badlands
3 copies - 3 average
City of Brass
3 copies - 3 average
Blood Moon
3 copies - 3 average
Red Elemental Blast
3 copies - 3 average
Unsummon
3 copies - 3 average
Shatter
3 copies - 3 average
Counterspell
3 copies - 3 average
Psionic Blast
3 copies - 3 average
Control Magic
2 copies - 2 average
Artifact Blast
2 copies - 2 average
Gloom
2 copies - 2 average
Chain Lightning
2 copies - 2 average
Serendib Djinn
1 copies - 1 average
Black Lotus
1 copies - 1 average
Strip Mine
1 copies - 1 average