Most played cards in UR Counterburn:

2 Decks
Lightning Bolt
8 copies - 4 average
Shatter
8 copies - 4 average
Counterspell
7 copies - 3.5 average
Control Magic
5 copies - 2.5 average
Blue Elemental Blast
5 copies - 2.5 average
Psionic Blast
5 copies - 2.5 average
Red Elemental Blast
5 copies - 2.5 average
Mishra's Factory
4 copies - 2 average
Volcanic Island
4 copies - 2 average
Flying Men
4 copies - 2 average
Chain Lightning
4 copies - 2 average
City of Brass
4 copies - 2 average
Fireball
4 copies - 2 average
Serendib Efreet
4 copies - 2 average
Power Sink
3 copies - 1.5 average
Juggernaut
3 copies - 1.5 average
Disintegrate
3 copies - 1.5 average
Icy Manipulator
2 copies - 1 average
Jade Statue
2 copies - 1 average
Energy Flux
2 copies - 1 average