Most played cards in Yidris, Maelstrom Wielder:

4 Decks
Eternal Witness
4 copies - 1 average
Ponder
4 copies - 1 average
Wooded Foothills
4 copies - 1 average
Watery Grave
4 copies - 1 average
Stomping Ground
4 copies - 1 average
Verdant Catacombs
4 copies - 1 average
Volcanic Island
4 copies - 1 average
Windswept Heath
4 copies - 1 average
Liliana of the Veil
4 copies - 1 average
Arid Mesa
4 copies - 1 average
Go for the Throat
4 copies - 1 average
Demonic Tutor
4 copies - 1 average
Jace, the Mind Sculptor
4 copies - 1 average
Brainstorm
4 copies - 1 average
Lightning Bolt
4 copies - 1 average
Abrupt Decay
4 copies - 1 average
Ancestral Vision
4 copies - 1 average
Steam Vents
4 copies - 1 average
Underground Sea
4 copies - 1 average
Mana Confluence
4 copies - 1 average