Most played cards in Twin Exarch:

4 Decks
Scalding Tarn
16 copies - 4 average
Lightning Bolt
16 copies - 4 average
Splinter Twin
15 copies - 3.75 average
Remand
14 copies - 3.5 average
Steam Vents
14 copies - 3.5 average
Deceiver Exarch
14 copies - 3.5 average
Preordain
12 copies - 3 average
Snapcaster Mage
12 copies - 3 average
Spirebluff Canal
10 copies - 2.5 average
Polluted Delta
9 copies - 2.25 average
Spellskite
8 copies - 2 average
Blood Moon
8 copies - 2 average
Sensei's Divining Top
8 copies - 2 average
Opt
8 copies - 2 average
Counterbalance
8 copies - 2 average
Anger of the Gods
6 copies - 1.5 average
Spell Pierce
6 copies - 1.5 average
Misty Rainforest
5 copies - 1.25 average
Sulfur Falls
5 copies - 1.25 average
Flooded Strand
5 copies - 1.25 average