Most played cards in Oath:

2 Decks
Accumulated Knowledge
8 copies - 4 average
Yavimaya Coast
8 copies - 4 average
Counterspell
8 copies - 4 average
Exploration
8 copies - 4 average
Oath of Druids
8 copies - 4 average
Moment's Peace
6 copies - 3 average
Back to Basics
6 copies - 3 average
Horn of Greed
6 copies - 3 average
Propaganda
6 copies - 3 average
Gush
6 copies - 3 average
Intuition
6 copies - 3 average
Hydroblast
6 copies - 3 average
Morphling
4 copies - 2 average
Naturalize
4 copies - 2 average
Krosan Reclamation
4 copies - 2 average
Misdirection
4 copies - 2 average
Mana Leak
4 copies - 2 average
Curfew
4 copies - 2 average
Capsize
2 copies - 1 average
Battlefield Scrounger
2 copies - 1 average