Most played cards in RUG Delver:

2 Decks
Force of Will
8 copies - 4 average
Lightning Bolt
8 copies - 4 average
Stifle
8 copies - 4 average
Ponder
8 copies - 4 average
Daze
8 copies - 4 average
Wasteland
8 copies - 4 average
Brainstorm
8 copies - 4 average
Delver of Secrets
8 copies - 4 average
Tarmogoyf
7 copies - 3.5 average
Flooded Strand
6 copies - 3 average
Volcanic Island
6 copies - 3 average
Murktide Regent
6 copies - 3 average
Tropical Island
6 copies - 3 average
Surgical Extraction
4 copies - 2 average
Red Elemental Blast
4 copies - 2 average
Pyroblast
4 copies - 2 average
Spell Pierce
4 copies - 2 average
Misty Rainforest
4 copies - 2 average
Minsc & Boo, Timeless Heroes
4 copies - 2 average
Meltdown
4 copies - 2 average