Most played cards in Rakdos:

1 Decks
Lightning Bolt
4 copies - 4 average
Bloodstained Mire
4 copies - 4 average
Unearth
4 copies - 4 average
Young Pyromancer
4 copies - 4 average
Cabal Therapy
4 copies - 4 average
Surgical Extraction
4 copies - 4 average
Badlands
4 copies - 4 average
Lightning Skelemental
4 copies - 4 average
Dreadhorde Arcanist
4 copies - 4 average
Thoughtseize
3 copies - 3 average
Marsh Flats
2 copies - 2 average
Abrade
2 copies - 2 average
Pyroblast
2 copies - 2 average
Plague Engineer
2 copies - 2 average
Null Rod
2 copies - 2 average
Blood Moon
2 copies - 2 average
Scalding Tarn
2 copies - 2 average
Kolaghan's Command
2 copies - 2 average
Inquisition of Kozilek
2 copies - 2 average
Liliana's Triumph
2 copies - 2 average