Most played cards in URW composition:

2 Decks
Serendib Efreet
8 copies - 4 average
Chain Lightning
8 copies - 4 average
City of Brass
8 copies - 4 average
Black Vise
8 copies - 4 average
Savannah Lions
8 copies - 4 average
Lightning Bolt
8 copies - 4 average
Disenchant
8 copies - 4 average
Psionic Blast
7 copies - 3.5 average
Volcanic Island
7 copies - 3.5 average
Tundra
7 copies - 3.5 average
Plateau
7 copies - 3.5 average
Divine Offering
6 copies - 3 average
Strip Mine
5 copies - 2.5 average
Mishra's Factory
5 copies - 2.5 average
Spirit Link
3 copies - 1.5 average
Blue Elemental Blast
3 copies - 1.5 average
Red Elemental Blast
3 copies - 1.5 average
Balance
2 copies - 1 average
Circle of Protection: Red
2 copies - 1 average
Time Walk
2 copies - 1 average