Most played cards in UR Delver:

2 Decks
Lightning Bolt
8 copies - 4 average
Force of Will
8 copies - 4 average
Ponder
8 copies - 4 average
Preordain
8 copies - 4 average
Wasteland
8 copies - 4 average
Daze
8 copies - 4 average
Scalding Tarn
8 copies - 4 average
Brainstorm
8 copies - 4 average
Dreadhorde Arcanist
8 copies - 4 average
Delver of Secrets
8 copies - 4 average
Pyroblast
6 copies - 3 average
Young Pyromancer
6 copies - 3 average
Volcanic Island
5 copies - 2.5 average
True-Name Nemesis
4 copies - 2 average
Spell Pierce
4 copies - 2 average
Flusterstorm
4 copies - 2 average
Flooded Strand
4 copies - 2 average
Narset, Parter of Veils
3 copies - 1.5 average
Surgical Extraction
3 copies - 1.5 average
Polluted Delta
3 copies - 1.5 average